MOTOROLA MC68HC908QT2 M68hc08microcontroller Datasheet

MC68HC908QY4
MC68HC908QT4
MC68HC908QY2
MC68HC908QT2
MC68HC908QY1
MC68HC908QT1
Data Sheet
M68HC08
Microcontrollers
MC68HC908QY4/D
Rev 3.0
1/2004
MOTOROLA.COM/SEMICONDUCTORS
MC68HC908QY4
MC68HC908QT4
MC68HC908QY2
MC68HC908QT2
MC68HC908QY1
MC68HC908QT1
Data Sheet
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revision. To verify you have the latest information available, refer to:
http://motorola.com/semiconductors/
The following revision history table summarizes changes contained in this
document. For your convenience, the page number designators have been linked
to the appropriate location.
Motorola and the Stylized M Logo are registered trademarks of Motorola, Inc.
DigitalDNA is a trademark of Motorola, Inc.
This product incorporates SuperFlash® technology licensed from SST.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
© Motorola, Inc., 2004
Data Sheet
3
Revision History
Revision History
Date
Revision
Level
September,
2002
N/A
December,
2002
January,
2003
0.1
0.2
Initial release
N/A
1.2 Features — Added 8-pin dual flat no lead (DFN) packages to features list.
19
Figure 1-2. MCU Pin Assignments — Figure updated to include DFN
packages.
21
Figure 2-1. Memory Map — Clarified illegal address and unimplemented
memory.
28
Figure 2-2. Control, Status, and Data Registers — Corrected bit definitions
for Port A Data Register (PTA) and Data Direction Register A (DDRA).
28
Table 13-3. Interrupt Sources — Corrected vector addresses for keyboard
interrupt and ADC conversion complete interrupt.
124
Section 13. System Integration Module (SIM) — Removed reference to break
status register as it is duplicated in break module.
113
11.3.1 Internal Oscillator and 11.3.1.1 Internal Oscillator Trimming —
Clarified oscillator trim option ordering information and what to expect with
untrimmed device.
97
Figure 11-5. Oscillator Trim Register (OSCTRIM) — Bit 1 designation
corrected.
104
Figure 15-13. Monitor Mode Circuit (Internal Clock, No High Voltage) —
Diagram updated for clarity.
160
Figure 12-1. I/O Port Register Summary — Corrected bit definitions for PTA7,
DDRA7, and DDRA6.
105
Figure 12-2. Port A Data Register (PTA) — Corrected bit definition for PTA7.
106
Figure 12-3. Data Direction Register A (DDRA) — Corrected bit definitions for
DDRA7 and DDRA6.
107
Figure 12-6. Port B Data Register (PTB) — Corrected bit definition for PTB1
109
Section 9. Keyboard Interrupt Module (KBI) — Section reworked after
deletion of auto wakeup for clarity.
83
Section 4. Auto Wakeup Module (AWU) — New section added for clarity.
49
Figure 10-1. LVI Module Block Diagram — Corrected LVI stop representation.
91
Section 16. Electrical Specifications — Extensive changes made to electrical
specifications.
169
17.5 8-Pin Dual Flat No Lead (DFN) Package (Case #1452) — Added case
outline drawing for DFN package.
187
Section 17. Ordering Information and Mechanical Specifications — Added
ordering information for DFN package.
185
4.2 Features — Corrected third bulleted item.
49
Data Sheet
4
Page
Number(s)
Description
MC68HC908QY/QT Family — Rev. 3
Revision History
MOTOROLA
Revision History
Revision History (Continued)
Date
August,
2003
Revision
Level
1.0
Description
Reformatted to meet latest M68HC08 documentation standards
N/A
Figure 1-1. Block Diagram — Diagram redrawn to include keyboard interrupt
module and TCLK pin designator.
20
Figure 1-2. MCU Pin Assignments — Added TCLK pin designator.
21
Table 1-2. Pin Functions — Added TCLK pin description.
22
Table 1-3. Function Priority in Shared Pins — Revised table for clarity and to
add TCLK.
23
Figure 2-1. Memory Map — Corrected names for the IRQ status and control
register (INTSCR) bits 3–0.
26
3.7.3 ADC Input Clock Register — Clarified bit description for the ADC clock
prescaler bits.
48
4.3 Functional Description — Updated periodic wakeup request values.
51
Figure 6-1. COP Block Diagram — Reworked for clarity
59
Section 8. External Interrupt (IRQ) — Corrected bit names for MODE, IRQF,
ACK, and IMASK
Section 14. Timer Interface Module (TIM) — Added TCLK function.
15.3 Monitor Module (MON) — Updated with additional data.
Section 16. Electrical Specifications — Updated with additional data.
October,
2003
January,
2004
2.0
3.0
77–81
131–147
156
169–183
Figure 2-2. Control, Status, and Data Registers — Deleted unimplemented
areas from $FFB0–$FFBD and $FFC2–$FFCF as they are actually available.
Also corrected $FFBF designation from unimplemented to reserved.
28
Figure 6-1. COP Block Diagram — Reworked for clarity
59
6.3.2 STOP Instruction — Added subsection
60
13.4.2 Active Resets from Internal Sources — Reworked notes for clarity.
117
Table 13-2. Reset Recovery Timing — Replaced previous table with new
information.
118
Section 14. Timer Interface Module (TIM) — Updated with additional data.
131
Figure 15-3. Break I/O Register Summary — Corrected bit designators for the
BRKAR register
151
15.3 Monitor Module (MON) — Clarified seventh bullet.
156
Table 17-1. MC Order Numbers — Corrected temperature and package
designators.
185
Figure 2-2. Control, Status, and Data Registers — Corrected reset state for
the FLASH Block Protect Register at address location $FFBE and the Internal
Oscillator Trim Value at $FFC0.
32
Figure 2-5. FLASH Block Protect Register (FLBPR) — Restated reset state
for clarity.
39
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Page
Number(s)
Data Sheet
Revision History
5
Revision History
Data Sheet
6
MC68HC908QY/QT Family — Rev. 3
Revision History
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
List of Sections
Section 1. General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Section 2. Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Section 3. Analog-to-Digital Converter (ADC) . . . . . . . . . . . . . . . . . . . 41
Section 4. Auto Wakeup Module (AWU) . . . . . . . . . . . . . . . . . . . . . . . . 49
Section 5. Configuration Register (CONFIG) . . . . . . . . . . . . . . . . . . . . 55
Section 6. Computer Operating Properly (COP) . . . . . . . . . . . . . . . . . 59
Section 7. Central Processor Unit (CPU) . . . . . . . . . . . . . . . . . . . . . . . 63
Section 8. External Interrupt (IRQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Section 9. Keyboard Interrupt Module (KBI) . . . . . . . . . . . . . . . . . . . . 83
Section 10. Low-Voltage Inhibit (LVI) . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Section 11. Oscillator Module (OSC). . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Section 12. Input/Output Ports (PORTS) . . . . . . . . . . . . . . . . . . . . . . 105
Section 13. System Integration Module (SIM) . . . . . . . . . . . . . . . . . . 113
Section 14. Timer Interface Module (TIM) . . . . . . . . . . . . . . . . . . . . . . 131
Section 15. Development Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Section 16. Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . 169
Section 17. Ordering Information and Mechanical
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
List of Sections
7
List of Sections
Data Sheet
8
MC68HC908QY/QT Family — Rev. 3
List of Sections
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Table of Contents
Section 1. General Description
1.1
1.2
1.3
1.4
1.5
1.6
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin Function Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
17
19
19
22
23
Section 2. Memory
2.1
2.2
2.3
2.4
2.5
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.6.5
2.6.6
2.6.7
2.6.8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Random-Access Memory (RAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Memory (FLASH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Page Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FLASH Block Protect Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25
25
25
27
33
34
34
35
36
36
37
39
40
40
Section 3. Analog-to-Digital Converter (ADC)
3.1
3.2
3.3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
3.4
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADC Port I/O Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conversion Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
41
41
43
44
44
44
44
44
45
Data Sheet
Table of Contents
9
Table of Contents
3.5
3.5.1
3.5.2
3.6
3.7
3.7.1
3.7.2
3.7.3
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADC Status and Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADC Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADC Input Clock Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45
45
45
45
45
46
47
48
Section 4. Auto Wakeup Module (AWU)
4.1
4.2
4.3
4.4
4.5
4.6
4.6.1
4.6.2
4.6.3
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Port A I/O Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Status and Control Register . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . . . . . . . .
49
49
50
51
51
51
52
52
53
Section 5. Configuration Register (CONFIG)
5.1
5.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Section 6. Computer Operating Properly (COP)
6.1
6.2
6.3
6.3.1
6.3.2
6.3.3
6.3.4
6.3.5
6.3.6
6.3.7
6.4
6.5
6.6
6.7
6.7.1
6.7.2
6.8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BUSCLKX4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COPD (COP Disable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Sheet
10
59
59
60
60
60
60
60
60
61
61
61
61
61
61
61
62
62
MC68HC908QY/QT Family — Rev. 3
Table of Contents
MOTOROLA
Table of Contents
Section 7. Central Processor Unit (CPU)
7.1
7.2
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.3.5
7.4
7.5
7.5.1
7.5.2
7.6
7.7
7.8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condition Code Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63
63
64
64
65
65
66
66
68
68
68
68
68
69
75
Section 8. External Interrupt (IRQ)
8.1
8.2
8.3
8.4
8.5
8.6
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . .
IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
77
77
77
80
81
81
Section 9. Keyboard Interrupt Module (KBI)
9.1
9.2
9.3
9.3.1
9.3.2
9.4
9.5
9.6
9.7
9.7.1
9.7.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . .
Input/Output Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Status and Control Register . . . . . . . . . . . . . . . . . . . . . . .
Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . . . . . . . .
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Table of Contents
Section 10. Low-Voltage Inhibit (LVI)
10.1
10.2
10.3
10.3.1
10.3.2
10.3.3
10.3.4
10.4
10.5
10.6
10.6.1
10.6.2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Polled LVI Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forced Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Hysteresis Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LVI Trip Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LVI Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LVI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
91
91
91
92
92
92
93
93
93
94
94
94
Section 11. Oscillator Module (OSC)
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
11.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
11.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
11.3.1
Internal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
11.3.1.1
Internal Oscillator Trimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
11.3.1.2
Internal to External Clock Switching . . . . . . . . . . . . . . . . . . . . . . . 97
11.3.2
External Oscillator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
11.3.3
XTAL Oscillator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
11.3.4
RC Oscillator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
11.4 Oscillator Module Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
11.4.1
Crystal Amplifier Input Pin (OSC1) . . . . . . . . . . . . . . . . . . . . . . . . . 100
11.4.2
Crystal Amplifier Output Pin (OSC2/PTA4/BUSCLKX4). . . . . . . . . 100
11.4.3
Oscillator Enable Signal (SIMOSCEN) . . . . . . . . . . . . . . . . . . . . . . 101
11.4.4
XTAL Oscillator Clock (XTALCLK) . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.4.5
RC Oscillator Clock (RCCLK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.4.6
Internal Oscillator Clock (INTCLK) . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.4.7
Oscillator Out 2 (BUSCLKX4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.4.8
Oscillator Out (BUSCLKX2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
11.5.1
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
11.5.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
11.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
11.7 CONFIG2 Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
11.8 Input/Output (I/O) Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
11.8.1
Oscillator Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
11.8.2
Oscillator Trim Register (OSCTRIM) . . . . . . . . . . . . . . . . . . . . . . . 104
Data Sheet
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Table of Contents
Section 12. Input/Output Ports (PORTS)
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2.1
Port A Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2.2
Data Direction Register A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2.3
Port A Input Pullup Enable Register . . . . . . . . . . . . . . . . . . . . . . . .
12.3 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.3.1
Port B Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.3.2
Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.3.3
Port B Input Pullup Enable Register . . . . . . . . . . . . . . . . . . . . . . . .
105
106
106
107
108
109
109
109
111
Section 13. System Integration Module (SIM)
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.2 RST and IRQ Pins Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . . . . . . .
13.3.1
Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.3.2
Clock Start-Up from POR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.3.3
Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . . . . . .
13.4 Reset and System Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.4.1
External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.4.2
Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . . . . . .
13.4.2.1
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.4.2.2
Computer Operating Properly (COP) Reset . . . . . . . . . . . . . . . .
13.4.2.3
Illegal Opcode Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.4.2.4
Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.4.2.5
Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . . . . . . .
13.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.5.1
SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . . . . . .
13.5.2
SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . . . . . . .
13.5.3
SIM Counter and Reset States . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.1
Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.1.1
Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.1.2
SWI Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.2
Interrupt Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.2.1
Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.2.2
Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.2.3
Interrupt Status Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.3
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.4
Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.6.5
Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . . . . . . .
13.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.7.1
Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.7.2
Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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116
116
116
116
116
117
117
117
118
119
120
120
120
120
120
121
121
121
121
123
124
124
125
125
126
126
126
126
127
127
128
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13.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
13.8.1
SIM Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
13.8.2
Break Flag Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Section 14. Timer Interface Module (TIM)
14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.3 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.1
TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.2
Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.3
Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.3.1
Unbuffered Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.3.2
Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.4
Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.4.4.1
Unbuffered PWM Signal Generation. . . . . . . . . . . . . . . . . . . . . .
14.4.4.2
Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . . . . . . . .
14.4.4.3
PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.6 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.7 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.8 Input/Output Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.8.1
TIM Clock Pin (PTA2/TCLK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.8.2
TIM Channel I/O Pins (PTA0/TCH0 and PTA1/TCH1) . . . . . . . . . .
14.9 Input/Output Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.9.1
TIM Status and Control Register . . . . . . . . . . . . . . . . . . . . . . . . . .
14.9.2
TIM Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.9.3
TIM Counter Modulo Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . .
14.9.4
TIM Channel Status and Control Registers . . . . . . . . . . . . . . . . . .
14.9.5
TIM Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
131
131
131
133
135
135
135
135
136
136
137
138
138
139
139
140
140
140
140
141
141
143
143
144
147
Section 15. Development Support
15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2 Break Module (BRK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.1
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.1.1
Flag Protection During Break Interrupts . . . . . . . . . . . . . . . . . . .
15.2.1.2
TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.1.3
COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.2
Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.2.1
Break Status and Control Register . . . . . . . . . . . . . . . . . . . . . . .
15.2.2.2
Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.2.3
Break Auxiliary Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.2.4
Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.2.5
Break Flag Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2.3
Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Sheet
14
149
149
149
152
152
152
153
153
154
154
155
155
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15.3 Monitor Module (MON) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.1
Normal Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.2
Forced Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.3
Monitor Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.4
Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.5
Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.6
Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1.7
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.2
Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
156
156
160
162
162
163
163
163
164
167
Section 16. Electrical Specifications
16.1
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
16.10
16.11
16.12
16.13
16.14
16.15
16.16
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-V DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical 5-V Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . .
5-V Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-V Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-V DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical 3.0-V Output Drive Characteristics. . . . . . . . . . . . . . . . . . . . . .
3-V Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-V Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supply Current Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog-to-Digital Converter Characteristics . . . . . . . . . . . . . . . . . . . . .
Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . . . . . . . .
Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
169
169
170
170
171
172
173
174
175
176
177
178
179
181
182
183
Section 17. Ordering Information
and Mechanical Specifications
17.1
17.2
17.3
17.4
17.5
17.6
17.7
17.8
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-Pin Plastic Dual In-Line Package (Case #626) . . . . . . . . . . . . . . . . .
8-Pin Small Outline Integrated Circuit Package (Case #968). . . . . . . .
8-Pin Dual Flat No Lead (DFN) Package (Case #1452). . . . . . . . . . . .
16-Pin Plastic Dual In-Line Package (Case #648D) . . . . . . . . . . . . . . .
16-Pin Small Outline Integrated Circuit Package (Case #751G) . . . . .
16-Pin Thin Shrink Small Outline Package (Case #948F) . . . . . . . . . .
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186
186
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Data Sheet — MC68HC908QY/QT Family
Section 1. General Description
1.1 Introduction
The MC68HC908QY4 is a member of the low-cost, high-performance M68HC08
Family of 8-bit microcontroller units (MCUs). The M68HC08 Family is a Complex
Instruction Set Computer (CISC) with a Von Neumann architecture. All MCUs in
the family use the enhanced M68HC08 central processor unit (CPU08) and are
available with a variety of modules, memory sizes and types, and package types.
0.4
Table 1-1. Summary of Device Variations
Device
FLASH
Memory Size
Analog-to-Digital
Converter
Pin
Count
MC68HC908QT1
1536 bytes
—
8 pins
MC68HC908QT2
1536 bytes
4 ch, 8 bit
8 pins
MC68HC908QT4
4096 bytes
4 ch, 8 bit
8 pins
MC68HC908QY1
1536 bytes
—
16 pins
MC68HC908QY2
1536 bytes
4 ch, 8 bit
16 pins
MC68HC908QY4
4096 bytes
4 ch, 8 bit
16 pins
1.2 Features
Features include:
•
High-performance M68HC08 CPU core
•
Fully upward-compatible object code with M68HC05 Family
•
5-V and 3-V operating voltages (VDD)
•
8-MHz internal bus operation at 5 V, 4-MHz at 3 V
•
Trimmable internal oscillator
– 3.2 MHz internal bus operation
– 8-bit trim capability allows 0.4% accuracy(1)
– ± 25% untrimmed
•
Auto wakeup from STOP capability
•
Configuration (CONFIG) register for MCU configuration options, including:
– Low-voltage inhibit (LVI) trip point
1. The oscillator frequency is guaranteed to ±5% over temperature and voltage range after trimming.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
General Description
17
General Description
•
In-system FLASH programming
•
FLASH security(1)
•
On-chip in-application programmable FLASH memory (with internal
program/erase voltage generation)
– MC68HC908QY4 and MC68HC908QT4 — 4096 bytes
– MC68HC908QY2, MC68HC908QY1, MC68HC908QT2, and
MC68HC908QT1 — 1536 bytes
•
128 bytes of on-chip random-access memory (RAM)
•
2-channel, 16-bit timer interface module (TIM)
•
4-channel, 8-bit analog-to-digital converter (ADC) on MC68HC908QY2,
MC68HC908QY4, MC68HC908QT2, and MC68HC908QT4
•
5 or 13 bidirectional input/output (I/O) lines and one input only:
– Six shared with keyboard interrupt function and ADC
– Two shared with timer channels
– One shared with external interrupt (IRQ)
– Eight extra I/O lines on 16-pin package only
– High current sink/source capability on all port pins
– Selectable pullups on all ports, selectable on an individual bit basis
– Three-state ability on all port pins
•
6-bit keyboard interrupt with wakeup feature (KBI)
•
Low-voltage inhibit (LVI) module features:
– Software selectable trip point in CONFIG register
•
System protection features:
– Computer operating properly (COP) watchdog
– Low-voltage detection with reset
– Illegal opcode detection with reset
– Illegal address detection with reset
•
External asynchronous interrupt pin with internal pullup (IRQ) shared with
general-purpose input pin
•
Master asynchronous reset pin (RST) shared with general-purpose
input/output (I/O) pin
•
Power-on reset
•
Internal pullups on IRQ and RST to reduce external components
•
Memory mapped I/O registers
•
Power saving stop and wait modes
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the FLASH difficult for unauthorized users.
Data Sheet
18
MC68HC908QY/QT Family — Rev. 3
General Description
MOTOROLA
General Description
MCU Block Diagram
•
MC68HC908QY4, MC68HC908QY2, and MC68HC908QY1 are available in
these packages:
– 16-pin plastic dual in-line package (PDIP)
– 16-pin small outline integrated circuit (SOIC) package
– 16-pin thin shrink small outline package (TSSOP)
•
MC68HC908QT4, MC68HC908QT2, and MC68HC908QT1 are available in
these packages:
– 8-pin PDIP
– 8-pin SOIC
– 8-pin dual flat no lead (DFN) package
Features of the CPU08 include the following:
•
Enhanced HC05 programming model
•
Extensive loop control functions
•
16 addressing modes (eight more than the HC05)
•
16-bit index register and stack pointer
•
Memory-to-memory data transfers
•
Fast 8 × 8 multiply instruction
•
Fast 16/8 divide instruction
•
Binary-coded decimal (BCD) instructions
•
Optimization for controller applications
•
Efficient C language support
1.3 MCU Block Diagram
Figure 1-1 shows the structure of the MC68HC908QY4.
1.4 Pin Assignments
The MC68HC908QT4, MC68HC908QT2, and MC68HC908QT1 are available in
8-pin packages and the MC68HC908QY4, MC68HC908QY2, and
MC68HC908QY1 in 16-pin packages. Figure 1-2 shows the pin assignment for
these packages.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
General Description
19
General Description
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 1-1. Block Diagram
Data Sheet
20
MC68HC908QY/QT Family — Rev. 3
General Description
MOTOROLA
General Description
Pin Assignments
VDD
1
8
VSS
PTA0/TCH0/KBI0
PTA5/OSC1/AD3/KBI5
2
7
PTA0/AD0/TCH0/KBI0
6
PTA1/TCH1/KBI1
PTA4/OSC2/AD2/KBI4
3
6
PTA1/AD1/TCH1/KBI1
5
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
4
5
PTA2/IRQ/KBI2/TCLK
VDD
1
8
VSS
PTA5/OSC1/KBI5
2
7
PTA4/OSC2/KBI4
3
PTA3/RST/KBI3
4
8-PIN ASSIGNMENT
MC68HC908QT1 PDIP/SOIC
8-PIN ASSIGNMENT
MC68HC908QT2 AND MC68HC908QT4 PDIP/SOIC
VDD
1
16
VSS
PTB0
PTB7
2
15
PTB0
14
PTB1
PTB6
3
14
PTB1
4
13
PTA0/TCH0/KBI0
PTA5/OSC1/AD3/KBI5
4
13
PTA0/AD0/TCH0/KBI0
PTA4/OSC2/KBI4
5
12
PTA1/TCH1/KBI1
PTA4/OSC2/AD2/KBI4
5
12
PTA1/AD1/TCH1/KBI1
PTB5
6
11
PTB2
PTB5
6
11
PTB2
PTB4
7
10
PTB3
PTB4
7
10
PTB3
PTA3/RST/KBI3
8
9
PTA3/RST/KBI3
8
9
VDD
1
16
VSS
PTB7
2
15
PTB6
3
PTA5/OSC1/KBI5
PTA2/IRQ/KBI2/TCLK
16-PIN ASSIGNMENT
MC68HC908QY2 AND MC68HC908QY4 PDIP/SOIC
16-PIN ASSIGNMENT
MC68HC908QY1 PDIP/SOIC
PTA0/TCH0/KBI0
PTB1
PTB0
VSS
VDD
PTB7
PTB6
PTA5/OSC1/KBI5
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PTA1/TCH1/KBI1
PTB2
PTB3
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
PTB4
PTB5
PTA4/OSC2/KBI4
PTA0/AD0/TCH0/KBI0
PTB1
PTB0
VSS
VDD
PTB7
PTB6
PTA5/OSC1/AD3/KBI5
16-PIN ASSIGNMENT
MC68HC908QY1 TSSOP
PTA0/TCH0/KBI0 1
PTA2/IRQ/KBI2/TCLK
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PTA1/AD1/TCH1/KBI1
PTB2
PTB3
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
PTB4
PTB5
PTA4/OSC2/AD2/KBI4
16-PIN ASSIGNMENT
MC68HC908QY2 AND MC68HC908QY4 TSSOP
8 PTA1/TCH1/KBI1
PTA0/AD0/TCH0/KBI0 1
8 PTA1/AD1/TCH1/KBI1
VSS 2
7 PTA2/IRQ/KBI2/TCLK
VSS 2
7 PTA2/IRQ/KBI2/TCLK
VDD 3
6 PTA3/RST/KBI3
VDD 3
6 PTA3/RST/KBI3
PTA5/OSC1/KB15 4
5 PTA4/OSC2/KBI4
PTA5//OSC1/AD3/KB15 4
8-PIN ASSIGNMENT
MC68HC908QT1 DFN
5 PTA4/OSC2/AD2/KBI4
8-PIN ASSIGNMENT
MC68HC908QT2 AND MC68HC908QT4 DFN
Figure 1-2. MCU Pin Assignments
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
General Description
21
General Description
1.5 Pin Functions
Table 1-2 provides a description of the pin functions.
Table 1-2. Pin Functions
Pin
Name
Description
Input/Output
VDD
Power supply
Power
VSS
Power supply ground
Power
PTA0 — General purpose I/O port
Input/Output
AD0 — A/D channel 0 input
Input
PTA0
TCH0 — Timer Channel 0 I/O
Input/Output
KBI0 — Keyboard interrupt input 0
Input
PTA1 — General purpose I/O port
Input/Output
AD1 — A/D channel 1 input
Input
PTA1
TCH1 — Timer Channel 1 I/O
Input/Output
KBI1 — Keyboard interrupt input 1
Input
PTA2 — General purpose input-only port
Input
IRQ — External interrupt with programmable pullup and Schmitt trigger input
Input
KBI2 — Keyboard interrupt input 2
Input
TCLK — Timer clock input
Input
PTA2
PTA3 — General purpose I/O port
PTA3
PTA4
Input/Output
RST — Reset input, active low with internal pullup and Schmitt trigger
Input
KBI3 — Keyboard interrupt input 3
Input
PTA4 — General purpose I/O port
Input/Output
OSC2 — XTAL oscillator output (XTAL option only)
RC or internal oscillator output (OSC2EN = 1 in PTAPUE register)
Output
Output
AD2 — A/D channel 2 input
Input
KBI4 — Keyboard interrupt input 4
Input
PTA5 — General purpose I/O port
Input/Output
OSC1 — XTAL, RC, or external oscillator input
Input
AD3 — A/D channel 3 input
Input
KBI5 — Keyboard interrupt input 5
Input
PTA5
PTB[0:7](1)
8 general-purpose I/O ports
Input/Output
1. The PTB pins are not available on the 8-pin packages.
Data Sheet
22
MC68HC908QY/QT Family — Rev. 3
General Description
MOTOROLA
General Description
Pin Function Priority
1.6 Pin Function Priority
Table 1-3 is meant to resolve the priority if multiple functions are enabled on a
single pin.
NOTE:
Upon reset all pins come up as input ports regardless of the priority table.
Table 1-3. Function Priority in Shared Pins
Pin Name
Highest-to-Lowest Priority Sequence
PTA0
AD0 → TCH0 → KBI0 → PTA0
PTA1
AD1 →TCH1 → KBI1 → PTA1
PTA2
IRQ → KBI2 → TCLK → PTA2
PTA3
RST → KBI3 → PTA3
PTA4
OSC2 → AD2 → KBI4 → PTA4
PTA5
OSC1 → AD3 → KBI5 → PTA5
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
General Description
23
General Description
Data Sheet
24
MC68HC908QY/QT Family — Rev. 3
General Description
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 2. Memory
2.1 Introduction
The central processor unit (CPU08) can address 64 Kbytes of memory space. The
memory map, shown in Figure 2-1, includes:
•
4096 bytes of user FLASH for MC68HC908QT4 and MC68HC908QY4
•
1536 bytes of user FLASH for MC68HC908QT2, MC68HC908QT1,
MC68HC908QY2, and MC68HC908QY1
•
128 bytes of random access memory (RAM)
•
48 bytes of user-defined vectors, located in FLASH
•
416 bytes of monitor read-only memory (ROM)
•
1536 bytes of FLASH program and erase routines, located in ROM
2.2 Unimplemented Memory Locations
Accessing an unimplemented location can have unpredictable effects on MCU
operation. In Figure 2-1 and in register figures in this document, unimplemented
locations are shaded.
2.3 Reserved Memory Locations
Accessing a reserved location can have unpredictable effects on MCU operation.
In Figure 2-1 and in register figures in this document, reserved locations are
marked with the word Reserved or with the letter R.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
25
Memory
$0000
↓
$003F
I/O REGISTERS
64 BYTES
$0040
↓
$007F
RESERVED(1)
64 BYTES
$0080
↓
$00FF
RAM
128 BYTES
$0100
↓
$27FF
UNIMPLEMENTED(1)
9984 BYTES
$2800
↓
$2DFF
AUXILIARY ROM
1536 BYTES
$2E00
↓
$EDFF
UNIMPLEMENTED(1)
49152 BYTES
$EE00
↓
$FDFF
FLASH MEMORY
MC68HC908QT4 AND MC68HC908QY4
4096 BYTES
Note 1.
Attempts to execute code from addresses in this
range will generate an illegal address reset.
$2E00
UNIMPLEMENTED
51712 BYTES
↓
$F7FF
$FE00
BREAK STATUS REGISTER (BSR)
$FE01
RESET STATUS REGISTER (SRSR)
$FE02
BREAK AUXILIARY REGISTER (BRKAR)
$FE03
BREAK FLAG CONTROL REGISTER (BFCR)
$FE04
INTERRUPT STATUS REGISTER 1 (INT1)
$FE05
INTERRUPT STATUS REGISTER 2 (INT2)
MC68HC908QT1, MC68HC908QT2,
MC68HC908QY1, and MC68HC908QY2
Memory Map
$FE06
INTERRUPT STATUS REGISTER 3 (INT3)
$FE07
RESERVED FOR FLASH TEST CONTROL REGISTER (FLTCR)
$FE08
FLASH CONTROL REGISTER (FLCR)
$FE09
BREAK ADDRESS HIGH REGISTER (BRKH)
$FE0A
BREAK ADDRESS LOW REGISTER (BRKL)
$FE0B
BREAK STATUS AND CONTROL REGISTER (BRKSCR)
$FE0C
LVISR
$FE0D
↓
$FE0F
RESERVED FOR FLASH TEST
3 BYTES
$FE10
↓
$FFAF
MONITOR ROM 416 BYTES
$FFB0
↓
$FFBD
FLASH
14 BYTES
$FFBE
FLASH BLOCK PROTECT REGISTER (FLBPR)
$FFBF
RESERVED FLASH
$FFC0
INTERNAL OSCILLATOR TRIM VALUE
$FFC1
RESERVED FLASH
$FFC2
↓
$FFCF
FLASH
14 BYTES
$FFD0
↓
$FFFF
USER VECTORS
48 BYTES
$F800
↓
$FDFF
FLASH MEMORY
1536 BYTES
Figure 2-1. Memory Map
Data Sheet
26
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
Input/Output (I/O) Section
2.4 Input/Output (I/O) Section
Addresses $0000–$003F, shown in Figure 2-2, contain most of the control, status,
and data registers. Additional I/O registers have these addresses:
•
$FE00 — Break status register, BSR
•
$FE01 — Reset status register, SRSR
•
$FE02 — Break auxiliary register, BRKAR
•
$FE03 — Break flag control register, BFCR
•
$FE04 — Interrupt status register 1, INT1
•
$FE05 — Interrupt status register 2, INT2
•
$FE06 — Interrupt status register 3, INT3
•
$FE07 — Reserved
•
$FE08 — FLASH control register, FLCR
•
$FE09 — Break address register high, BRKH
•
$FE0A — Break address register low, BRKL
•
$FE0B — Break status and control register, BRKSCR
•
$FE0C — LVI status register, LVISR
•
$FE0D — Reserved
•
$FFBE — FLASH block protect register, FLBPR
•
$FFC0 — Internal OSC trim value — Optional
•
$FFFF — COP control register, COPCTL
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
27
Memory
Addr.
Register Name
Bit 7
$0000
Port A Data Register Read:
(PTA) Write:
See page 106. Reset:
Port B Data Register Read:
(PTB) Write:
See page 109. Reset:
$0001
$0002
Unimplemented
$0003
Unimplemented
$0004
Data Direction Register A Read:
(DDRA) Write:
See page 107. Reset:
Read:
$0005
Data Direction Register B
(DDRB) Write:
See page 109. Reset:
$000C
4
3
2
PTA5
PTA4
PTA3
PTA2
1
Bit 0
PTA1
PTA0
PTB1
PTB0
DDRA1
DDRA0
Unaffected by reset
PTB7
PTB6
PTB5
PTB4
PTB3
PTB2
Unaffected by reset
0
R
R
DDRA5
DDRA4
DDRA3
0
0
0
0
0
0
0
0
DDRB7
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
0
PTAPUE5
PTAPUE4
PTAPUE3
PTAPUE2
PTAPUE1
PTAPUE0
0
0
0
0
0
0
0
PTBPUE6
PTBPUE5
PTBPUE4
PTBPUE3
PTBPUE2
PTBPUE1
PTBPUE0
0
0
0
0
0
0
0
0
0
0
KEYF
0
IMASKK
MODEK
Unimplemented
Port A Input Pullup Enable Read:
Register (PTAPUE) Write:
See page 108. Reset:
OSC2EN
0
Port B Input Pullup Enable Read: PTBPUE7
Register (PTBPUE) Write:
See page 111. Reset:
0
$000D
↓
$0019
Unimplemented
$001A
Keyboard Status and Read:
Control Register (KBSCR) Write:
See page 88. Reset:
$001B
AWUL
5
Unimplemented
$0006
↓
$000A
$000B
R
6
Keyboard Interrupt Read:
Enable Register (KBIER) Write:
See page 89. Reset:
0
0
ACKK
0
0
0
0
0
0
0
0
0
0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
0
0
0
0
0
0
0
R
= Reserved
= Unimplemented
U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 5)
Data Sheet
28
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
Input/Output (I/O) Section
Addr.
Register Name
$001C
$001D
$001E
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
IRQF
0
IMASK
MODE
0
0
0
R
R
RSTEN
0
0
0
0(2)
Unimplemented
IRQ Status and Control Read:
Register (INTSCR) Write:
See page 81. Reset:
Configuration Register 2 Read:
(CONFIG2)(1) Write:
See page 56. Reset:
ACK
0
0
0
IRQPUD
IRQEN
R
0
0
0
0
0
OSCOPT1 OSCOPT0
0
1. One-time writable register after each reset.
2. RSTEN reset to 0 by a power-on reset (POR) only.
$001F
Configuration Register 1 Read:
(CONFIG1)(1) Write:
See page 56. Reset:
COPRS
LVISTOP
LVIRSTD
LVIPWRD
LVI5OR3
SSREC
STOP
COPD
0
0
0
0
0(2)
0
0
0
PS2
PS1
PS0
1. One-time writable register after each reset.
2. LVI5OR3 reset to 0 by a power-on reset (POR) only.
$0020
$0021
$0022
$0023
$0024
$0025
TIM Status and Control Read:
Register (TSC) Write:
See page 141. Reset:
TOF
0
0
1
0
0
0
0
0
Read:
TIM Counter Register High
(TCNTH) Write:
See page 143. Reset:
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
0
0
0
0
0
0
0
0
Read:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
1
1
1
1
1
1
1
1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
1
1
1
1
1
1
1
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
TIM Counter Register Low
(TCNTL) Write:
See page 143. Reset:
TIM Counter Modulo Read:
Register High (TMODH) Write:
See page 143. Reset:
TIM Counter Modulo Read:
Register Low (TMODL) Write:
See page 143. Reset:
TIM Channel 0 Status and Read:
Control Register (TSC0) Write:
See page 144. Reset:
Read:
$0026
TIM Channel 0
Register High (TCH0H) Write:
See page 147. Reset:
0
CH0F
0
TOIE
TSTOP
0
0
TRST
Indeterminate after reset
= Unimplemented
R
= Reserved
U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 5)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
29
Memory
Addr.
Register Name
TIM Channel 0 Read:
Register Low (TCH0L) Write:
See page 147. Reset:
$0027
$0028
TIM Channel 1 Status and Read:
Control Register (TSC1) Write:
See page 144. Reset:
TIM Channel 1 Read:
Register High (TCH1H) Write:
See page 147. Reset:
$0029
TIM Channel 1 Read:
Register Low (TCH1L) Write:
See page 147. Reset:
$002A
$002B
↓
$0035
Unimplemented
$0036
Oscillator Status Register Read:
(OSCSTAT) Write:
See page 103. Reset:
$0037
Unimplemented
Read:
Oscillator Trim Register
(OSCTRIM)
See page 104.
Read:
$0038
Write:
Reset:
$0039
↓
$003B
Unimplemented
$003C
ADC Status and Control Read:
Register (ADSCR) Write:
See page 46. Reset:
$003D
Unimplemented
$003E
ADC Data Register Read:
(ADR) Write:
See page 47. Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Indeterminate after reset
CH1F
0
CH1IE
0
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 2
Bit 1
Bit 0
Indeterminate after reset
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Indeterminate after reset
ECGST
R
R
R
R
R
R
ECGON
0
0
0
0
0
0
0
0
TRIM7
TRIM6
TRIM5
TRIM4
TRIM3
TRIM2
TRIM1
TRIM0
1
0
0
0
0
0
0
0
AIEN
ADCO
CH4
CH3
CH2
CH1
CH0
0
0
0
1
1
1
1
1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
COCO
Indeterminate after reset
= Unimplemented
R
= Reserved
U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 5)
Data Sheet
30
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
Input/Output (I/O) Section
Addr.
$003F
Register Name
ADC Input Clock Register Read:
(ADICLK) Write:
See page 48. Reset:
Break Status Register Read:
(BSR) Write:
See page 155. Reset:
$FE00
Bit 7
6
5
4
3
2
1
Bit 0
ADIV2
ADIV1
ADIV0
0
0
0
0
0
0
0
0
0
0
0
0
0
R
R
R
R
R
R
SBSW
See note 1
R
0
1. Writing a 0 clears SBSW.
$FE01
SIM Reset Status Register
(SRSR)
See page 129.
PIN
COP
ILOP
ILAD
MODRST
LVI
0
POR:
1
0
0
0
0
0
0
0
Read:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
BCFE
R
R
R
R
R
R
R
0
IF5
IF4
IF3
0
IF1
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
IF14
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IF15
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
0
0
0
0
HVEN
MASS
ERASE
PGM
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
0
0
0
0
0
0
0
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
R
= Reserved
Write:
Break Flag Control Read:
Register (BFCR) Write:
See page 155. Reset:
$FE03
$FE05
POR
Break Auxiliary
Register (BRKAR) Write:
See page 154. Reset:
$FE02
$FE04
Read:
Interrupt Status Register 1 Read:
(INT1) Write:
See page 81. Reset:
Interrupt Status Register 2 Read:
(INT2) Write:
See page 81. Reset:
Read:
$FE06
Interrupt Status Register 3
(INT3) Write:
See page 81. Reset:
$FE07
$FE08
Reserved
FLASH Control Register Read:
(FLCR) Write:
See page 34. Reset:
Read:
$FE09
$FE0A
Break Address High
Register (BRKH) Write:
See page 154. Reset:
Break Address low Read:
Register (BRKL) Write:
See page 154. Reset:
BDCOP
0
= Unimplemented
U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 5)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
31
Memory
Addr.
$FE0B
Register Name
Break Status and Control Read:
Register (BRKSCR) Write:
See page 153. Reset:
LVI Status Register Read:
(LVISR) Write:
See page 93. Reset:
$FE0C
$FE0D
↓
$FE0F
Reserved for FLASH Test
$FFBE
FLASH Block Protect Read:
Register (FLBPR) Write:
See page 39. Reset:
$FFBF
Reserved
$FFC0
Internal Oscillator Trim
Value (Optional)
$FFC1
Reserved
Read:
Write:
Bit 7
6
5
4
3
2
1
Bit 0
BRKE
BRKA
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LVIOUT
0
0
0
0
0
0
R
0
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
BPR7
BPR6
BPR5
BPR4
BPR3
BPR2
BPR1
BPR0
Unaffected by reset
R
R
R
R
R
R
R
R
TRIM7
TRIM6
TRIM5
TRIM4
TRIM3
TRIM2
TRIM1
TRIM0
R
R
R
R
R
R
Reset:
$FFFF
COP Control Register Read:
(COPCTL) Write:
See page 61. Reset:
Unaffected by reset
R
R
LOW BYTE OF RESET VECTOR
WRITING CLEARS COP COUNTER (ANY VALUE)
Unaffected by reset
= Unimplemented
R
= Reserved
U = Unaffected
Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 5)
Data Sheet
32
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
Random-Access Memory (RAM)
.
Table 2-1. Vector Addresses
Vector Priority
Lowest
Vector
Address
Vector
$FFDE
ADC conversion complete vector (high)
$FFDF
ADC conversion complete vector (low)
$FFE0
Keyboard vector (high)
$FFE1
Keyboard vector (low)
IF15
IF14
IF13
↓
IF6
—
Not used
$FFF2
TIM overflow vector (high)
$FFF3
TIM overflow vector (low)
$FFF4
TIM Channel 1 vector (high)
$FFF5
TIM Channel 1 vector (low)
$FFF6
TIM Channel 0 vector (high)
$FFF7
TIM Channel 0 vector (low)
IF5
IF4
IF3
IF2
—
Not used
$FFFA
IRQ vector (high)
$FFFB
IRQ vector (low)
$FFFC
SWI vector (high)
$FFFD
SWI vector (low)
$FFFE
Reset vector (high)
$FFFF
Reset vector (low)
IF1
—
Highest
—
2.5 Random-Access Memory (RAM)
Addresses $0080–$00FF are RAM locations. The location of the stack RAM is
programmable. The 16-bit stack pointer allows the stack to be anywhere in the
64-Kbyte memory space.
NOTE:
For correct operation, the stack pointer must point only to RAM locations.
Before processing an interrupt, the central processor unit (CPU) uses five bytes of
the stack to save the contents of the CPU registers.
NOTE:
For M6805, M146805, and M68HC05 compatibility, the H register is not stacked.
During a subroutine call, the CPU uses two bytes of the stack to store the return
address. The stack pointer decrements during pushes and increments during pulls.
NOTE:
Be careful when using nested subroutines. The CPU may overwrite data in the
RAM during a subroutine or during the interrupt stacking operation.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
33
Memory
2.6 FLASH Memory (FLASH)
This subsection describes the operation of the embedded FLASH memory. The
FLASH memory can be read, programmed, and erased from a single external
supply. The program and erase operations are enabled through the use of an
internal charge pump.
The FLASH memory consists of an array of 4096 or 1536 bytes with an additional
48 bytes for user vectors. The minimum size of FLASH memory that can be erased
is 64 bytes; and the maximum size of FLASH memory that can be programmed in
a program cycle is 32 bytes (a row). Program and erase operations are facilitated
through control bits in the FLASH control register (FLCR). Details for these
operations appear later in this section. The address ranges for the user memory
and vectors are:
NOTE:
•
$EE00 – $FDFF; user memory, 4096 bytes: MC68HC908QY4 and
MC68HC908QT4
•
$F800 – $FDFF; user memory, 1536 bytes: MC68HC908QY2,
MC68HC908QT2, MC68HC908QY1 and MC68HC908QT1
•
$FFD0 – $FFFF; user interrupt vectors, 48 bytes.
An erased bit reads as a 1 and a programmed bit reads as a 0.
A security feature prevents viewing of the FLASH contents.(1)
2.6.1 FLASH Control Register
The FLASH control register (FLCR) controls FLASH program and erase
operations.
Address:
Read:
$FE08
Bit 7
6
5
4
0
0
0
0
0
0
0
0
Write:
Reset:
3
2
1
Bit 0
HVEN
MASS
ERASE
PGM
0
0
0
0
Figure 2-3. FLASH Control Register (FLCR)
HVEN — High Voltage Enable Bit
This read/write bit enables high voltage from the charge pump to the memory
for either program or erase operation. It can only be set if either PGM =1 or
ERASE =1 and the proper sequence for program or erase is followed.
1 = High voltage enabled to array and charge pump on
0 = High voltage disabled to array and charge pump off
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the FLASH difficult for unauthorized users.
Data Sheet
34
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
FLASH Memory (FLASH)
MASS — Mass Erase Control Bit
This read/write bit configures the memory for mass erase operation.
1 = Mass erase operation selected
0 = Mass erase operation unselected
ERASE — Erase Control Bit
This read/write bit configures the memory for erase operation. ERASE is
interlocked with the PGM bit such that both bits cannot be equal to 1 or set to 1
at the same time.
1 = Erase operation selected
0 = Erase operation unselected
PGM — Program Control Bit
This read/write bit configures the memory for program operation. PGM is
interlocked with the ERASE bit such that both bits cannot be equal to 1 or set
to 1 at the same time.
1 = Program operation selected
0 = Program operation unselected
2.6.2 FLASH Page Erase Operation
Use the following procedure to erase a page of FLASH memory. A page consists
of 64 consecutive bytes starting from addresses $XX00, $XX40, $XX80, or $XXC0.
The 48-byte user interrupt vectors area also forms a page. Any FLASH memory
page can be erased alone.
1. Set the ERASE bit and clear the MASS bit in the FLASH control register.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the address range of the block
to be erased.
4. Wait for a time, tNVS (minimum 10 µs).
5. Set the HVEN bit.
6. Wait for a time, tErase (minimum 1 ms or 4 ms).
7. Clear the ERASE bit.
8. Wait for a time, tNVH (minimum 5 µs).
9. Clear the HVEN bit.
10. After time, tRCV (typical 1 µs), the memory can be accessed in read mode
again.
NOTE:
CAUTION:
Programming and erasing of FLASH locations cannot be performed by code being
executed from the FLASH memory. While these operations must be performed in
the order as shown, but other unrelated operations may occur between the steps.
A page erase of the vector page will erase the internal oscillator trim value at
$FFC0.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
35
Memory
In applications that require more than 1000 program/erase cycles, use the 4 ms
page erase specification to get improved long-term reliability. Any application can
use this 4 ms page erase specification. However, in applications where a FLASH
location will be erased and reprogrammed less than 1000 times, and speed is
important, use the 1 ms page erase specification to get a shorter cycle time.
2.6.3 FLASH Mass Erase Operation
Use the following procedure to erase the entire FLASH memory to read as a 1:
1. Set both the ERASE bit and the MASS bit in the FLASH control register.
2. Read the FLASH block protect register.
3. Write any data to any FLASH address(1) within the FLASH memory address
range.
4. Wait for a time, tNVS (minimum 10 µs).
5. Set the HVEN bit.
6. Wait for a time, tMErase (minimum 4 ms).
7. Clear the ERASE and MASS bits.
NOTE:
Mass erase is disabled whenever any block is protected (FLBPR does not equal
$FF).
8. Wait for a time, tNVHL (minimum 100 µs).
9. Clear the HVEN bit.
10. After time, tRCV (typical 1 µs), the memory can be accessed in read mode
again.
NOTE:
CAUTION:
Programming and erasing of FLASH locations cannot be performed by code being
executed from the FLASH memory. While these operations must be performed in
the order as shown, but other unrelated operations may occur between the steps.
A mass erase will erase the internal oscillator trim value at $FFC0.
2.6.4 FLASH Program Operation
Programming of the FLASH memory is done on a row basis. A row consists of 32
consecutive bytes starting from addresses $XX00, $XX20, $XX40, $XX60, $XX80,
$XXA0, $XXC0, or $XXE0. Use the following step-by-step procedure to program a
row of FLASH memory
Figure 2-4 shows a flowchart of the programming algorithm.
NOTE:
Only bytes which are currently $FF may be programmed.
1. When in monitor mode, with security sequence failed (see 15.3.2 Security), write to the FLASH
block protect register instead of any FLASH address.
Data Sheet
36
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
FLASH Memory (FLASH)
1. Set the PGM bit. This configures the memory for program operation and
enables the latching of address and data for programming.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the address range desired.
4. Wait for a time, tNVS (minimum 10 µs).
5. Set the HVEN bit.
6. Wait for a time, tPGS (minimum 5 µs).
7. Write data to the FLASH address being programmed(1).
8. Wait for time, tPROG (minimum 30 µs).
9. Repeat step 7 and 8 until all desired bytes within the row are programmed.
10. Clear the PGM bit(1).
11. Wait for time, tNVH (minimum 5 µs).
12. Clear the HVEN bit.
13. After time, tRCV (typical 1 µs), the memory can be accessed in read mode
again.
NOTE:
The COP register at location $FFFF should not be written between steps 5–12,
when the HVEN bit is set. Since this register is located at a valid FLASH address,
unpredictable behavior may occur if this location is written while HVEN is set.
This program sequence is repeated throughout the memory until all data is
programmed.
NOTE:
Programming and erasing of FLASH locations cannot be performed by code being
executed from the FLASH memory. While these operations must be performed in
the order shown, other unrelated operations may occur between the steps. Do not
exceed tPROG maximum, see 16.16 Memory Characteristics.
2.6.5 FLASH Protection
Due to the ability of the on-board charge pump to erase and program the FLASH
memory in the target application, provision is made to protect blocks of memory
from unintentional erase or program operations due to system malfunction. This
protection is done by use of a FLASH block protect register (FLBPR). The FLBPR
determines the range of the FLASH memory which is to be protected. The range
of the protected area starts from a location defined by FLBPR and ends to the
bottom of the FLASH memory ($FFFF). When the memory is protected, the HVEN
bit cannot be set in either ERASE or PROGRAM operations.
NOTE:
In performing a program or erase operation, the FLASH block protect register must
be read after setting the PGM or ERASE bit and before asserting the HVEN bit.
1. The time between each FLASH address change, or the time between the last FLASH address
programmed to clearing PGM bit, must not exceed the maximum programming time, tPROG
maximum.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
37
Memory
Algorithm for Programming
a Row (32 Bytes) of FLASH Memory
1
SET PGM BIT
2 READ THE FLASH BLOCK PROTECT REGISTER
3
WRITE ANY DATA TO ANY FLASH ADDRESS
WITHIN THE ROW ADDRESS RANGE DESIRED
4
WAIT FOR A TIME, tNVS
5
SET HVEN BIT
6
WAIT FOR A TIME, tPGS
7
WRITE DATA TO THE FLASH ADDRESS
TO BE PROGRAMMED
8
WAIT FOR A TIME, tPROG
9
COMPLETED
PROGRAMMING
THIS ROW?
Y
N
10
CLEAR PGM BIT
11
WAIT FOR A TIME, tNVH
12
NOTES:
The time between each FLASH address change (step 7 to step 7),
or the time between the last FLASH address programmed
to clearing PGM bit (step 7 to step 10)
must not exceed the maximum programming
time, tPROG max.
CLEAR HVEN BIT
13
WAIT FOR A TIME, tRCV
END OF PROGRAMMING
This row program algorithm assumes the row/s
to be programmed are initially erased.
Figure 2-4. FLASH Programming Flowchart
Data Sheet
38
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Memory
FLASH Memory (FLASH)
When the FLBPR is programmed with all 0 s, the entire memory is protected from
being programmed and erased. When all the bits are erased (all 1’s), the entire
memory is accessible for program and erase.
When bits within the FLBPR are programmed, they lock a block of memory. The
address ranges are shown in 2.6.6 FLASH Block Protect Register. Once the
FLBPR is programmed with a value other than $FF, any erase or program of the
FLBPR or the protected block of FLASH memory is prohibited. Mass erase is
disabled whenever any block is protected (FLBPR does not equal $FF). The
FLBPR itself can be erased or programmed only with an external voltage, VTST,
present on the IRQ pin. This voltage also allows entry from reset into the monitor
mode.
2.6.6 FLASH Block Protect Register
The FLASH block protect register is implemented as a byte within the FLASH
memory, and therefore can only be written during a programming sequence of the
FLASH memory. The value in this register determines the starting address of the
protected range within the FLASH memory.
Address:
Read:
Write:
$FFBE
Bit 7
6
5
4
3
2
1
Bit 0
BPR7
BPR6
BPR5
BPR4
BPR3
BPR2
BPR1
BPR0
Reset:
Unaffected by reset. Initial value from factory is 1.
Write to this register is by a programming sequence to the FLASH memory.
Figure 2-5. FLASH Block Protect Register (FLBPR)
BPR[7:0] — FLASH Protection Register Bits [7:0]
These eight bits in FLBPR represent bits [13:6] of a 16-bit memory address. Bits
[15:14] are 1s and bits [5:0] are 0s.
The resultant 16-bit address is used for specifying the start address of the
FLASH memory for block protection. The FLASH is protected from this start
address to the end of FLASH memory, at $FFFF. With this mechanism, the
protect start address can be XX00, XX40, XX80, or XXC0 within the FLASH
memory. See Figure 2-6 and Table 2-2.
16-BIT MEMORY ADDRESS
START ADDRESS OF
FLASH BLOCK PROTECT
1
1
FLBPR VALUE
0
0
0
0
0
0
Figure 2-6. FLASH Block Protect Start Address
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Memory
39
Memory
Table 2-2. Examples of Protect Start Address
BPR[7:0]
Start of Address of Protect Range
$00–$B8
The entire FLASH memory is protected.
$B9 (1011 1001)
$EE40 (1110 1110 0100 0000)
$BA (1011 1010)
$EE80 (1110 1110 1000 0000)
$BB (1011 1011)
$EEC0 (1110 1110 1100 0000)
$BC (1011 1100)
$EF00 (1110 1111 0000 0000)
and so on...
$DE (1101 1110)
$F780 (1111 0111 1000 0000)
$DF (1101 1111)
$F7C0 (1111 0111 1100 0000)
$FE (1111 1110)
$FF80 (1111 1111 1000 0000)
FLBPR, OSCTRIM, and vectors are protected
$FF
The entire FLASH memory is not protected.
2.6.7 Wait Mode
Putting the MCU into wait mode while the FLASH is in read mode does not affect
the operation of the FLASH memory directly, but there will not be any memory
activity since the CPU is inactive.
The WAIT instruction should not be executed while performing a program or erase
operation on the FLASH, or the operation will discontinue and the FLASH will be
on standby mode.
2.6.8 Stop Mode
Putting the MCU into stop mode while the FLASH is in read mode does not affect
the operation of the FLASH memory directly, but there will not be any memory
activity since the CPU is inactive.
The STOP instruction should not be executed while performing a program or erase
operation on the FLASH, or the operation will discontinue and the FLASH will be
on standby mode
NOTE:
Standby mode is the power-saving mode of the FLASH module in which all internal
control signals to the FLASH are inactive and the current consumption of the
FLASH is at a minimum.
Data Sheet
40
MC68HC908QY/QT Family — Rev. 3
Memory
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 3. Analog-to-Digital Converter (ADC)
3.1 Introduction
This section describes the analog-to-digital converter (ADC). The ADC is an 8-bit,
4-channel analog-to-digital converter. The ADC module is only available on the
MC68HC908QY2, MC68HC908QT2, MC68HC908QY4, and MC68HC908QT4.
3.2 Features
Features of the ADC module include:
•
4 channels with multiplexed input
•
Linear successive approximation with monotonicity
•
8-bit resolution
•
Single or continuous conversion
•
Conversion complete flag or conversion complete interrupt
•
Selectable ADC clock frequency
Figure 3-1 provides a summary of the input/output (I/O) registers.
Addr.
Register Name
ADC Status and Control
Register (ADSCR)
See page 46.
$003C
$003D
Unimplemented
$003E
ADC Data Register
(ADR)
See page 47.
$003F
ADC Input Clock Register
(ADICLK)
See page 48.
Bit 7
Read:
COCO
Write:
6
5
4
3
2
1
Bit 0
AIEN
ADCO
CH4
CH3
CH2
CH1
CH0
Reset:
0
0
0
1
1
1
1
1
Read:
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Write:
Reset:
Read:
Write:
Reset:
Indeterminate after reset
ADIV2
ADIV1
ADIV0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented
Figure 3-1. ADC I/O Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Analog-to-Digital Converter (ADC)
41
Analog-to-Digital Converter (ADC)
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 3-2. Block Diagram Highlighting ADC Block and Pins
Data Sheet
42
MC68HC908QY/QT Family — Rev. 3
Analog-to-Digital Converter (ADC)
MOTOROLA
Analog-to-Digital Converter (ADC)
Functional Description
3.3 Functional Description
Four ADC channels are available for sampling external sources at pins PTA0,
PTA1, PTA4, and PTA5. An analog multiplexer allows the single ADC converter to
select one of the four ADC channels as an ADC voltage input (ADCVIN). ADCVIN
is converted by the successive approximation register-based counters. The ADC
resolution is eight bits. When the conversion is completed, ADC puts the result in
the ADC data register and sets a flag or generates an interrupt.
Figure 3-3 shows a block diagram of the ADC.
INTERNAL
DATA BUS
READ DDRA
DISABLE
WRITE DDRA
DDRAx
RESET
WRITE PTA
ADCx
PTAx
READ PTA
DISABLE
ADC CHANNEL x
ADC DATA REGISTER
INTERRUPT
LOGIC
AIEN
CONVERSION
COMPLETE
COCO
BUS CLOCK
ADC VOLTAGE IN
ADCVIN
ADC
CHANNEL
SELECT
(1 OF 4 CHANNELS)
CH[4:0]
ADC CLOCK
CLOCK
GENERATOR
ADIV[2:0]
Figure 3-3. ADC Block Diagram
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Analog-to-Digital Converter (ADC)
43
Analog-to-Digital Converter (ADC)
3.3.1 ADC Port I/O Pins
PTA0, PTA1, PTA4, and PTA5 are general-purpose I/O pins that are shared with
the ADC channels. The channel select bits (ADC status and control register
(ADSCR), $003C), define which ADC channel/port pin will be used as the input
signal. The ADC overrides the port I/O logic by forcing that pin as input to the ADC.
The remaining ADC channels/port pins are controlled by the port I/O logic and can
be used as general-purpose I/O. Writes to the port register or data direction register
(DDR) will not have any affect on the port pin that is selected by the ADC. Read of
a port pin which is in use by the ADC will return a 0 if the corresponding DDR bit is
at 0. If the DDR bit is at 1, the value in the port data latch is read.
3.3.2 Voltage Conversion
When the input voltage to the ADC equals VDD, the ADC converts the signal to $FF
(full scale). If the input voltage equals VSS, the ADC converts it to $00. Input
voltages between VDD and VSS are a straight-line linear conversion. All other input
voltages will result in $FF if greater than VDD and $00 if less than VSS.
NOTE:
Input voltage should not exceed the analog supply voltages.
3.3.3 Conversion Time
Sixteen ADC internal clocks are required to perform one conversion. The ADC
starts a conversion on the first rising edge of the ADC internal clock immediately
following a write to the ADSCR. If the ADC internal clock is selected to run at
1 MHz, then one conversion will take 16 µs to complete. With a 1-MHz ADC
internal clock the maximum sample rate is 62.5 kHz.
Conversion Time =
16 ADC Clock Cycles
ADC Clock Frequency
Number of Bus Cycles = Conversion Time × Bus Frequency
3.3.4 Continuous Conversion
In the continuous conversion mode (ADCO = 1), the ADC continuously converts
the selected channel filling the ADC data register (ADR) with new data after each
conversion. Data from the previous conversion will be overwritten whether that
data has been read or not. Conversions will continue until the ADCO bit is cleared.
The COCO bit (ADSCR, $003C) is set after each conversion and will stay set until
the next read of the ADC data register.
When a conversion is in process and the ADSCR is written, the current conversion
data should be discarded to prevent an incorrect reading.
3.3.5 Accuracy and Precision
The conversion process is monotonic and has no missing codes.
Data Sheet
44
MC68HC908QY/QT Family — Rev. 3
Analog-to-Digital Converter (ADC)
MOTOROLA
Analog-to-Digital Converter (ADC)
Interrupts
3.4 Interrupts
When the AIEN bit is set, the ADC module is capable of generating a central
processor unit (CPU) interrupt after each ADC conversion. A CPU interrupt is
generated if the COCO bit is at 0. The COCO bit is not used as a conversion
complete flag when interrupts are enabled.
3.5 Low-Power Modes
The following subsections describe the ADC in low-power modes.
3.5.1 Wait Mode
The ADC continues normal operation during wait mode. Any enabled CPU interrupt
request from the ADC can bring the microcontroller unit (MCU) out of wait mode. If
the ADC is not required to bring the MCU out of wait mode, power down the ADC
by setting the CH[4:0] bits in ADSCR to 1s before executing the WAIT instruction.
3.5.2 Stop Mode
The ADC module is inactive after the execution of a STOP instruction. Any pending
conversion is aborted. ADC conversions resume when the MCU exits stop mode.
Allow one conversion cycle to stabilize the analog circuitry before using ADC data
after exiting stop mode.
3.6 Input/Output Signals
The ADC module has four channels that are shared with I/O port A.
ADC voltage in (ADCVIN) is the input voltage signal from one of the four ADC
channels to the ADC module.
3.7 Input/Output Registers
These I/O registers control and monitor ADC operation:
•
ADC status and control register (ADSCR)
•
ADC data register (ADR)
•
ADC clock register (ADICLK)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Analog-to-Digital Converter (ADC)
45
Analog-to-Digital Converter (ADC)
3.7.1 ADC Status and Control Register
The following paragraphs describe the function of the ADC status and control
register (ADSCR). When a conversion is in process and the ADSCR is written, the
current conversion data should be discarded to prevent an incorrect reading.
Address: $003C
Bit 7
Read:
COCO
Write:
Reset:
0
6
5
4
3
2
1
Bit 0
AIEN
ADCO
CH4
CH3
CH2
CH1
CH0
0
0
1
1
1
1
1
= Unimplemented
Figure 3-4. ADC Status and Control Register (ADSCR)
COCO — Conversions Complete Bit
In non-interrupt mode (AIEN = 0), COCO is a read-only bit that is set at the end
of each conversion. COCO will stay set until cleared by a read of the ADC data
register. Reset clears this bit.
In interrupt mode (AIEN = 1), COCO is a read-only bit that is not set at the end
of a conversion. It always reads as a 0.
1 = Conversion completed (AIEN = 0)
0 = Conversion not completed (AIEN = 0) or CPU interrupt enabled
(AIEN = 1)
NOTE:
The write function of the COCO bit is reserved. When writing to the ADSCR
register, always have a 0 in the COCO bit position.
AIEN — ADC Interrupt Enable Bit
When this bit is set, an interrupt is generated at the end of an ADC conversion.
The interrupt signal is cleared when ADR is read or ADSCR is written. Reset
clears the AIEN bit.
1 = ADC interrupt enabled
0 = ADC interrupt disabled
ADCO — ADC Continuous Conversion Bit
When set, the ADC will convert samples continuously and update ADR at the
end of each conversion. Only one conversion is allowed when this bit is cleared.
Reset clears the ADCO bit.
1 = Continuous ADC conversion
0 = One ADC conversion
CH[4:0] — ADC Channel Select Bits
CH4, CH3, CH2, CH1, and CH0 form a 5-bit field which is used to select one of
the four ADC channels. The five select bits are detailed in Table 3-1. Care
should be taken when using a port pin as both an analog and a digital input
simultaneously to prevent switching noise from corrupting the analog signal.
Data Sheet
46
MC68HC908QY/QT Family — Rev. 3
Analog-to-Digital Converter (ADC)
MOTOROLA
Analog-to-Digital Converter (ADC)
Input/Output Registers
The ADC subsystem is turned off when the channel select bits are all set to 1.
This feature allows for reduced power consumption for the MCU when the ADC
is not used. Reset sets all of these bits to 1.
NOTE:
Recovery from the disabled state requires one conversion cycle to stabilize.
Table 3-1. MUX Channel Select
CH4
CH3
CH2
CH1
CH0
ADC
Channel
Input Select
0
0
0
0
0
ADC0
PTA0
0
0
0
0
1
ADC1
PTA1
0
0
0
1
0
ADC2
PTA4
0
0
0
1
1
ADC3
PTA5
0
0
1
0
0
—
↓
↓
↓
↓
↓
—
1
1
0
1
0
—
1
1
0
1
1
—
Reserved
1
1
1
0
0
—
Unused
1
1
1
0
1
—
VDDA(2)
1
1
1
1
0
—
VSSA(2)
1
1
1
1
1
—
ADC power off
Unused(1)
1. If any unused channels are selected, the resulting ADC conversion will be
unknown.
2. The voltage levels supplied from internal reference nodes, as specified in the
table, are used to verify the operation of the ADC converter both in production test and for user applications.
3.7.2 ADC Data Register
One 8-bit result register is provided. This register is updated each time an ADC
conversion completes.
Address: $003E
Read:
Bit 7
6
5
4
3
2
1
Bit 0
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Write:
Reset:
Indeterminate after reset
= Unimplemented
Figure 3-5. ADC Data Register (ADR)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Analog-to-Digital Converter (ADC)
47
Analog-to-Digital Converter (ADC)
3.7.3 ADC Input Clock Register
This register selects the clock frequency for the ADC.
Address: $003F
Bit 7
Read:
Write:
Reset:
6
5
ADIV2
ADIV1
ADIV0
0
0
0
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
= Unimplemented
Figure 3-6. ADC Input Clock Register (ADICLK)
ADIV2–ADIV0 — ADC Clock Prescaler Bits
ADIV2, ADIV1, and ADIV0 form a 3-bit field which selects the divide ratio used
by the ADC to generate the internal ADC clock. Table 3-2 shows the available
clock configurations. The ADC clock frequency should be set between fADIC(MIN)
and fADIC(MAX). The analog input level should remain stable for the entire
conversion time (maximum = 17 ADC clock cycles).
Table 3-2. ADC Clock Divide Ratio
ADIV2
ADIV1
ADIV0
ADC Clock Rate
0
0
0
Bus clock ÷ 1
0
0
1
Bus clock ÷ 2
0
1
0
Bus clock ÷ 4
0
1
1
Bus clock ÷ 8
1
X
X
Bus clock ÷ 16
X = don’t care
Data Sheet
48
MC68HC908QY/QT Family — Rev. 3
Analog-to-Digital Converter (ADC)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 4. Auto Wakeup Module (AWU)
4.1 Introduction
This section describes the auto wakeup module (AWU). The AWU generates a
periodic interrupt during stop mode to wake the part up without requiring an
external signal. Figure 4-2 is a block diagram of the AWU.
4.2 Features
Features of the auto wakeup module include:
•
One internal interrupt with separate interrupt enable bit, sharing the same
keyboard interrupt vector and keyboard interrupt mask bit
•
Exit from low-power stop mode without external signals
•
Selectable timeout periods
•
Dedicated low-power internal oscillator separate from the main system clock
sources
Figure 4-1 provides a summary of the input/output (I/O) registers used in
conjuction with the AWU.
Addr.
Register Name
$0000
$001A
$001B
Bit 7
6
Port A Data Register Read:
(PTA) Write:
See page 52. Reset:
0
AWUL
Keyboard Status Read:
and Control Register Write:
(KBSCR)
See page 52. Reset:
0
Keyboard Interrupt Enable Read:
Register (KBIER) Write:
See page 53. Reset:
5
4
3
PTA5
PTA4
PTA3
2
PTA2
1
Bit 0
PTA1
PTA0
IMASKK
MODEK
Unaffected by reset
0
0
0
KEYF
0
ACKK
0
0
0
0
0
0
0
0
0
0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
0
0
0
0
0
0
0
= Unimplemented
Figure 4-1. AWU Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Auto Wakeup Module (AWU)
49
Auto Wakeup Module (AWU)
4.3 Functional Description
The function of the auto wakeup logic is to generate periodic wakeup requests to
bring the microcontroller unit (MCU) out of stop mode. The wakeup requests are
treated as regular keyboard interrupt requests, with the difference that instead of a
pin, the interrupt signal is generated by an internal logic.
Writing the AWUIE bit in the keyboard interrupt enable register enables or disables
the auto wakeup interrupt input (see Figure 4-2). A logic 1 applied to the
AWUIREQ input with auto wakeup interrupt request enabled, latches an auto
wakeup interrupt request.
Auto wakeup latch, AWUL, can be read directly from the bit 6 position of port A data
register (PTA). This is a read-only bit which is occupying an empty bit position on
PTA. No PTA associated registers, such as PTA6 data direction or PTA6 pullup
exist for this bit.
Entering stop mode will enable the auto wakeup generation logic. An internal RC
oscillator (exclusive for the auto wakeup feature) drives the wakeup request
generator. Once the overflow count is reached in the generator counter, a wakeup
request, AWUIREQ, is latched and sent to the KBI logic. See Figure 4-1.
Wakeup interrupt requests will only be serviced if the associated interrupt enable
bit, AWUIE, in KBIER is set. The AWU shares the keyboard interrupt vector.
COPRS (FROM CONFIG1)
VDD
AUTOWUGEN
TO PTA READ, BIT 6
1 = DIV 29
SHORT 0 = DIV 214
OVERFLOW
INT RC OSC
EN
D
32 kHz
CLK
E
RST
AWUL
Q
AWUIREQ
R
TO KBI INTERRUPT LOGIC (SEE
Figure 9-3. Keyboard Interrupt
Block Diagram)
CLRLOGIC
RESET
CLEAR
ACKK
(CGMXCLK)
BUSCLKX4
CLK
RST
RESET
ISTOP
RESET
AWUIE
Figure 4-2. Auto Wakeup Interrupt Request Generation Logic
Data Sheet
50
MC68HC908QY/QT Family — Rev. 3
Auto Wakeup Module (AWU)
MOTOROLA
Auto Wakeup Module (AWU)
Wait Mode
The overflow count can be selected from two options defined by the COPRS bit in
CONFIG1. This bit was “borrowed” from the computer operating properly (COP)
using the fact that the COP feature is idle (no MCU clock available) in stop mode.
The typical values of the periodic wakeup request are (at room temperature):
•
COPRS = 0: 650 ms @ 5 V, 875 ms @ 3 V
•
COPRS = 1: 16 ms @ 5 V, 22 ms @ 3 V
The auto wakeup RC oscillator is highly dependent on operating voltage and
temperature. This feature is not recommended for use as a time-keeping function.
The wakeup request is latched to allow the interrupt source identification. The
latched value, AWUL, can be read directly from the bit 6 position of PTA data
register. This is a read-only bit which is occupying an empty bit position on PTA.
No PTA associated registers, such as PTA6 data, PTA6 direction, and PTA6 pullup
exist for this bit. The latch can be cleared by writing to the ACKK bit in the KBSCR
register. Reset also clears the latch. AWUIE bit in KBI interrupt enable register (see
Figure 4-2) has no effect on AWUL reading.
The AWU oscillator and counters are inactive in normal operating mode and
become active only upon entering stop mode.
4.4 Wait Mode
The AWU module remains inactive in wait mode.
4.5 Stop Mode
When the AWU module is enabled (AWUIE = 1 in the keyboard interrupt enable
register) it is activated automatically upon entering stop mode. Clearing the
IMASKK bit in the keyboard status and control register enables keyboard interrupt
requests to bring the MCU out of stop mode. The AWU counters start from ‘0’ each
time stop mode is entered.
4.6 Input/Output Registers
The AWU shares registers with the keyboard interrupt (KBI) module and the port A
I/O module. The following I/O registers control and monitor operation of the AWU:
•
Port A data register (PTA)
•
Keyboard interrupt status and control register (KBSCR)
•
Keyboard interrupt enable register (KBIER)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Auto Wakeup Module (AWU)
51
Auto Wakeup Module (AWU)
4.6.1 Port A I/O Register
The port A data register (PTA) contains a data latch for the state of the AWU
interrupt request, in addition to the data latches for port A.
Address: $0000
Read:
Bit 7
6
0
AWUL
0
0
Write:
Reset:
5
4
3
2
PTA5
PTA4
PTA3
PTA2
1
Bit 0
PTA1
PTA0
Unaffected by reset
= Unimplemented
Figure 4-3. Port A Data Register (PTA)
AWUL — Auto Wakeup Latch
This is a read-only bit which has the value of the auto wakeup interrupt request
latch. The wakeup request signal is generated internally. There is no PTA6 port
or any of the associated bits such as PTA6 data direction or pullup bits.
1 = Auto wakeup interrupt request is pending
0 = Auto wakeup interrupt request is not pending
NOTE:
PTA5–PTA0 bits are not used in conjuction with the auto wakeup feature. To see
a description of these bits, see 12.2.1 Port A Data Register.
4.6.2 Keyboard Status and Control Register
The keyboard status and control register (KBSCR):
•
Flags keyboard/auto wakeup interrupt requests
•
Acknowledges keyboard/auto wakeup interrupt requests
•
Masks keyboard/auto wakeup interrupt requests
Address: $001A
Read:
Bit 7
6
5
4
3
2
0
0
0
0
KEYF
0
Write:
Reset:
ACKK
0
0
0
0
0
0
1
Bit 0
IMASKK
MODEK
0
0
= Unimplemented
Figure 4-4. Keyboard Status and Control Register (KBSCR)
Bits 7–4 — Not used
These read-only bits always read as 0s.
KEYF — Keyboard Flag Bit
This read-only bit is set when a keyboard interrupt is pending on port A or auto
wakeup. Reset clears the KEYF bit.
1 = Keyboard/auto wakeup interrupt pending
0 = No keyboard/auto wakeup interrupt pending
Data Sheet
52
MC68HC908QY/QT Family — Rev. 3
Auto Wakeup Module (AWU)
MOTOROLA
Auto Wakeup Module (AWU)
Input/Output Registers
ACKK — Keyboard Acknowledge Bit
Writing a 1 to this write-only bit clears the keyboard/auto wakeup interrupt
request on port A and auto wakeup logic. ACKK always reads as 0.Reset clears
ACKK.
IMASKK— Keyboard Interrupt Mask Bit
Writing a 1 to this read/write bit prevents the output of the keyboard interrupt
mask from generating interrupt requests on port A or auto wakeup. Reset clears
the IMASKK bit.
1 = Keyboard/auto wakeup interrupt requests masked
0 = Keyboard/auto wakeup interrupt requests not masked
NOTE:
MODEK is not used in conjuction with the auto wakeup feature. To see a
description of this bit, see 9.7.1 Keyboard Status and Control Register.
4.6.3 Keyboard Interrupt Enable Register
The keyboard interrupt enable register (KBIER) enables or disables the auto
wakeup to operate as a keyboard/auto wakeup interrupt input.
Address: $001B
Bit 7
Read:
0
Write:
Reset:
0
6
5
4
3
2
1
Bit 0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
0
0
0
0
0
0
0
= Unimplemented
Figure 4-5. Keyboard Interrupt Enable Register (KBIER)
AWUIE — Auto Wakeup Interrupt Enable Bit
This read/write bit enables the auto wakeup interrupt input to latch interrupt
requests. Reset clears AWUIE.
1 = Auto wakeup enabled as interrupt input
0 = Auto wakeup not enabled as interrupt input
NOTE:
KBIE5–KBIE0 bits are not used in conjuction with the auto wakeup feature. To see
a description of these bits, see 9.7.2 Keyboard Interrupt Enable Register.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Auto Wakeup Module (AWU)
53
Auto Wakeup Module (AWU)
Data Sheet
54
MC68HC908QY/QT Family — Rev. 3
Auto Wakeup Module (AWU)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 5. Configuration Register (CONFIG)
5.1 Introduction
This section describes the configuration registers (CONFIG1 and CONFIG2). The
configuration registers enable or disable the following options:
•
Stop mode recovery time (32 × BUSCLKX4 cycles or
4096 × BUSCLKX4 cycles)
•
STOP instruction
•
Computer operating properly module (COP)
•
COP reset period (COPRS): (213 –24) × BUSCLKX4 or
(218 –24) × BUSCLKX4
•
Low-voltage inhibit (LVI) enable and trip voltage selection
•
OSC option selection
•
IRQ pin
•
RST pin
•
Auto wakeup timeout period
5.2 Functional Description
The configuration registers are used in the initialization of various options. The
configuration registers can be written once after each reset. Most of the
configuration register bits are cleared during reset. Since the various options affect
the operation of the microcontroller unit (MCU) it is recommended that this register
be written immediately after reset. The configuration registers are located at $001E
and $001F, and may be read at anytime.
NOTE:
The CONFIG registers are one-time writable by the user after each reset. Upon
a reset, the CONFIG registers default to predetermined settings as shown in
Figure 5-1 and Figure 5-2.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Configuration Register (CONFIG)
55
Configuration Register (CONFIG)
Address: $001E
Bit 7
6
5
4
3
2
1
Bit 0
IRQPUD
IRQEN
R
OSCOPT1
OSCOPT0
R
R
RSTEN
Reset:
0
0
0
0
0
0
0
U
POR:
0
0
0
0
0
0
0
0
R
= Reserved
Read:
Write:
U = Unaffected
Figure 5-1. Configuration Register 2 (CONFIG2)
IRQPUD — IRQ Pin Pullup Control Bit
1 = Internal pullup is disconnected
0 = Internal pullup is connected between IRQ pin and VDD
IRQEN — IRQ Pin Function Selection Bit
1 = Interrupt request function active in pin
0 = Interrupt request function inactive in pin
OSCOPT1 and OSCOPT0 — Selection Bits for Oscillator Option
(0, 0) Internal oscillator
(0, 1) External oscillator
(1, 0) External RC oscillator
(1, 1) External XTAL oscillator
RSTEN — RST Pin Function Selection
1 = Reset function active in pin
0 = Reset function inactive in pin
NOTE:
The RSTEN bit is cleared by a power-on reset (POR) only. Other resets will leave
this bit unaffected.
Address: $001F
Bit 7
6
5
4
3
2
1
Bit 0
COPRS
LVISTOP
LVIRSTD
LVIPWRD
LVI5OR3
SSREC
STOP
COPD
Reset:
0
0
0
0
U
0
0
0
POR:
0
0
0
0
0
0
0
0
Read:
Write:
U = Unaffected
Figure 5-2. Configuration Register 1 (CONFIG1)
COPRS (Out of STOP Mode) — COP Reset Period Selection Bit
1 = COP reset short cycle = (213 – 24) × BUSCLKX4
0 = COP reset long cycle = (218 – 24) × BUSCLKX4
COPRS (In STOP Mode) — Auto Wakeup Period Selection Bit
1 = Auto wakeup short cycle = (29) × INTRCOSC
0 = Auto wakeup long cycle = (214) × INTRCOSC
Data Sheet
56
MC68HC908QY/QT Family — Rev. 3
Configuration Register (CONFIG)
MOTOROLA
Configuration Register (CONFIG)
Functional Description
LVISTOP — LVI Enable in Stop Mode Bit
When the LVIPWRD bit is clear, setting the LVISTOP bit enables the LVI to
operate during stop mode. Reset clears LVISTOP.
1 = LVI enabled during stop mode
0 = LVI disabled during stop mode
LVIRSTD — LVI Reset Disable Bit
LVIRSTD disables the reset signal from the LVI module.
1 = LVI module resets disabled
0 = LVI module resets enabled
LVIPWRD — LVI Power Disable Bit
LVIPWRD disables the LVI module.
1 = LVI module power disabled
0 = LVI module power enabled
LVI5OR3 — LVI 5-V or 3-V Operating Mode Bit
LVI5OR3 selects the voltage operating mode of the LVI module. The voltage
mode selected for the LVI should match the operating VDD for the LVI’s voltage
trip points for each of the modes.
1 = LVI operates in 5-V mode
0 = LVI operates in 3-V mode
NOTE:
The LVI5OR3 bit is cleared by a power-on reset (POR) only. Other resets will leave
this bit unaffected.
SSREC — Short Stop Recovery Bit
SSREC enables the CPU to exit stop mode with a delay of 32 BUSCLKX4
cycles instead of a 4096 BUSCLKX4 cycle delay.
1 = Stop mode recovery after 32 BUSCLKX4 cycles
0 = Stop mode recovery after 4096 BUSCLKX4 cycles
NOTE:
Exiting stop mode by an LVI reset will result in the long stop recovery.
When using the LVI during normal operation but disabling during stop mode, the
LVI will have an enable time of tEN. The system stabilization time for power-on
reset and long stop recovery (both 4096 BUSCLKX4 cycles) gives a delay
longer than the LVI enable time for these startup scenarios. There is no period
where the MCU is not protected from a low-power condition. However, when
using the short stop recovery configuration option, the 32 BUSCLKX4 delay
must be greater than the LVI’s turn on time to avoid a period in startup where
the LVI is not protecting the MCU.
STOP — STOP Instruction Enable Bit
STOP enables the STOP instruction.
1 = STOP instruction enabled
0 = STOP instruction treated as illegal opcode
COPD — COP Disable Bit
COPD disables the COP module.
1 = COP module disabled
0 = COP module enabled
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Configuration Register (CONFIG)
57
Configuration Register (CONFIG)
Data Sheet
58
MC68HC908QY/QT Family — Rev. 3
Configuration Register (CONFIG)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 6. Computer Operating Properly (COP)
6.1 Introduction
The computer operating properly (COP) module contains a free-running counter
that generates a reset if allowed to overflow. The COP module helps software
recover from runaway code. Prevent a COP reset by clearing the COP counter
periodically. The COP module can be disabled through the COPD bit in the
configuration 1 (CONFIG1) register.
6.2 Functional Description
INTERNAL RESET SOURCES
RESET STATUS REGISTER
COP TIMEOUT
CLEAR STAGES 5–12
STOP INSTRUCTION
RESET CIRCUIT
12-BIT SIM COUNTER
CLEAR ALL STAGES
BUSCLKX4
COPCTL WRITE
COP CLOCK
COPEN (FROM SIM)
COP DISABLE (COPD FROM CONFIG1)
RESET
COPCTL WRITE
6-BIT COP COUNTER
CLEAR
COP COUNTER
COP RATE SELECT
(COPRS FROM CONFIG1)
Figure 6-1. COP Block Diagram
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Computer Operating Properly (COP)
59
Computer Operating Properly (COP)
The COP counter is a free-running 6-bit counter preceded by the 12-bit system
integration module (SIM) counter. If not cleared by software, the COP counter
overflows and generates an asynchronous reset after 218 – 24 or 213 – 24
BUSCLKX4 cycles; depending on the state of the COP rate select bit, COPRS, in
configuration register 1. With a 218 – 24 BUSCLKX4 cycle overflow option, the
internal 12.8-MHz oscillator gives a COP timeout period of 20.48 ms. Writing any
value to location $FFFF before an overflow occurs prevents a COP reset by
clearing the COP counter and stages 12–5 of the SIM counter.
NOTE:
Service the COP immediately after reset and before entering or after exiting stop
mode to guarantee the maximum time before the first COP counter overflow.
A COP reset pulls the RST pin low (if the RSTEN bit is set in the CONFIG1 register)
for 32 × BUSCLKX4 cycles and sets the COP bit in the reset status register (RSR).
See 13.8.1 SIM Reset Status Register.
NOTE:
Place COP clearing instructions in the main program and not in an interrupt
subroutine. Such an interrupt subroutine could keep the COP from generating a
reset even while the main program is not working properly.
6.3 I/O Signals
The following paragraphs describe the signals shown in Figure 6-1.
6.3.1 BUSCLKX4
BUSCLKX4 is the oscillator output signal. BUSCLKX4 frequency is equal to the
crystal frequency or the RC-oscillator frequency.
6.3.2 STOP Instruction
The STOP instruction clears the SIM counter.
6.3.3 COPCTL Write
Writing any value to the COP control register (COPCTL) (see 6.4 COP Control
Register) clears the COP counter and clears stages 12–5 of the SIM counter.
Reading the COP control register returns the low byte of the reset vector.
6.3.4 Power-On Reset
The power-on reset (POR) circuit in the SIM clears the SIM counter
4096 × BUSCLKX4 cycles after power up.
6.3.5 Internal Reset
An internal reset clears the SIM counter and the COP counter.
Data Sheet
60
MC68HC908QY/QT Family — Rev. 3
Computer Operating Properly (COP)
MOTOROLA
Computer Operating Properly (COP)
COP Control Register
6.3.6 COPD (COP Disable)
The COPD signal reflects the state of the COP disable bit (COPD) in the
configuration register 1 (CONFIG1). See Section 5. Configuration Register
(CONFIG).
6.3.7 COPRS (COP Rate Select)
The COPRS signal reflects the state of the COP rate select bit (COPRS) in the
configuration register 1 (CONFIG1). See Section 5. Configuration Register
(CONFIG).
6.4 COP Control Register
The COP control register (COPCTL) is located at address $FFFF and overlaps the
reset vector. Writing any value to $FFFF clears the COP counter and starts a new
timeout period. Reading location $FFFF returns the low byte of the reset vector.
Address: $FFFF
Bit 7
6
5
4
3
Read:
LOW BYTE OF RESET VECTOR
Write:
CLEAR COP COUNTER
Reset:
Unaffected by reset
2
1
Bit 0
Figure 6-2. COP Control Register (COPCTL)
6.5 Interrupts
The COP does not generate CPU interrupt requests.
6.6 Monitor Mode
The COP is disabled in monitor mode when VTST is present on the IRQ pin.
6.7 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby
modes.
6.7.1 Wait Mode
The COP continues to operate during wait mode. To prevent a COP reset during
wait mode, periodically clear the COP counter.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Computer Operating Properly (COP)
61
Computer Operating Properly (COP)
6.7.2 Stop Mode
Stop mode turns off the BUSCLKX4 input to the COP and clears the SIM counter.
Service the COP immediately before entering or after exiting stop mode to ensure
a full COP timeout period after entering or exiting stop mode.
6.8 COP Module During Break Mode
The COP is disabled during a break interrupt with monitor mode when BDCOP bit
is set in break auxiliary register (BRKAR).
Data Sheet
62
MC68HC908QY/QT Family — Rev. 3
Computer Operating Properly (COP)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 7. Central Processor Unit (CPU)
7.1 Introduction
The M68HC08 CPU (central processor unit) is an enhanced and fully
object-code-compatible version of the M68HC05 CPU. The CPU08 Reference
Manual (Motorola document order number CPU08RM/AD) contains a description
of the CPU instruction set, addressing modes, and architecture.
7.2 Features
Features of the CPU include:
•
Object code fully upward-compatible with M68HC05 Family
•
16-bit stack pointer with stack manipulation instructions
•
16-bit index register with x-register manipulation instructions
•
8-MHz CPU internal bus frequency
•
64-Kbyte program/data memory space
•
16 addressing modes
•
Memory-to-memory data moves without using accumulator
•
Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions
•
Enhanced binary-coded decimal (BCD) data handling
•
Modular architecture with expandable internal bus definition for extension
of addressing range beyond 64 Kbytes
•
Low-power stop and wait modes
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Central Processor Unit (CPU)
63
Central Processor Unit (CPU)
7.3 CPU Registers
Figure 7-1 shows the five CPU registers. CPU registers are not part of the memory
map.
0
7
ACCUMULATOR (A)
0
15
H
X
INDEX REGISTER (H:X)
15
0
STACK POINTER (SP)
15
0
PROGRAM COUNTER (PC)
7
0
V 1 1 H I N Z C
CONDITION CODE REGISTER (CCR)
CARRY/BORROW FLAG
ZERO FLAG
NEGATIVE FLAG
INTERRUPT MASK
HALF-CARRY FLAG
TWO’S COMPLEMENT OVERFLOW FLAG
Figure 7-1. CPU Registers
7.3.1 Accumulator
The accumulator is a general-purpose 8-bit register. The CPU uses the
accumulator to hold operands and the results of arithmetic/logic operations.
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Write:
Reset:
Unaffected by reset
Figure 7-2. Accumulator (A)
Data Sheet
64
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
CPU Registers
7.3.2 Index Register
The 16-bit index register allows indexed addressing of a 64-Kbyte memory space.
H is the upper byte of the index register, and X is the lower byte. H:X is the
concatenated 16-bit index register.
In the indexed addressing modes, the CPU uses the contents of the index register
to determine the conditional address of the operand.
The index register can serve also as a temporary data storage location.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit
0
0
0
0
0
0
0
0
0
X
X
X
X
X
X
X
X
Read:
Write:
Reset:
X = Indeterminate
Figure 7-3. Index Register (H:X)
7.3.3 Stack Pointer
The stack pointer is a 16-bit register that contains the address of the next location
on the stack. During a reset, the stack pointer is preset to $00FF. The reset stack
pointer (RSP) instruction sets the least significant byte to $FF and does not affect
the most significant byte. The stack pointer decrements as data is pushed onto the
stack and increments as data is pulled from the stack.
In the stack pointer 8-bit offset and 16-bit offset addressing modes, the stack
pointer can function as an index register to access data on the stack. The CPU
uses the contents of the stack pointer to determine the conditional address of the
operand.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Bit
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Read:
Write:
Reset:
Figure 7-4. Stack Pointer (SP)
NOTE:
The location of the stack is arbitrary and may be relocated anywhere in
random-access memory (RAM). Moving the SP out of page 0 ($0000 to $00FF)
frees direct address (page 0) space. For correct operation, the stack pointer must
point only to RAM locations.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Central Processor Unit (CPU)
65
Central Processor Unit (CPU)
7.3.4 Program Counter
The program counter is a 16-bit register that contains the address of the next
instruction or operand to be fetched.
Normally, the program counter automatically increments to the next sequential
memory location every time an instruction or operand is fetched. Jump, branch,
and interrupt operations load the program counter with an address other than that
of the next sequential location.
During reset, the program counter is loaded with the reset vector address located
at $FFFE and $FFFF. The vector address is the address of the first instruction to
be executed after exiting the reset state.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
Bit
0
1
Read:
Write:
Reset:
Loaded with vector from $FFFE and $FFFF
Figure 7-5. Program Counter (PC)
7.3.5 Condition Code Register
The 8-bit condition code register contains the interrupt mask and five flags that
indicate the results of the instruction just executed. Bits 6 and 5 are set
permanently to 1. The following paragraphs describe the functions of the condition
code register.
Bit 7
6
5
4
3
2
1
Bit 0
V
1
1
H
I
N
Z
C
X
1
1
X
1
X
X
X
Read:
Write:
Reset:
X = Indeterminate
Figure 7-6. Condition Code Register (CCR)
V — Overflow Flag
The CPU sets the overflow flag when a two's complement overflow occurs. The
signed branch instructions BGT, BGE, BLE, and BLT use the overflow flag.
1 = Overflow
0 = No overflow
Data Sheet
66
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
CPU Registers
H — Half-Carry Flag
The CPU sets the half-carry flag when a carry occurs between accumulator bits
3 and 4 during an add-without-carry (ADD) or add-with-carry (ADC) operation.
The half-carry flag is required for binary-coded decimal (BCD) arithmetic
operations. The DAA instruction uses the states of the H and C flags to
determine the appropriate correction factor.
1 = Carry between bits 3 and 4
0 = No carry between bits 3 and 4
I — Interrupt Mask
When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU
interrupts are enabled when the interrupt mask is cleared. When a CPU
interrupt occurs, the interrupt mask is set
automatically after the CPU registers are saved on the stack, but before the
interrupt vector is fetched.
1 = Interrupts disabled
0 = Interrupts enabled
NOTE:
To maintain M6805 Family compatibility, the upper byte of the index register (H) is
not stacked automatically. If the interrupt service routine modifies H, then the user
must stack and unstack H using the PSHH and PULH instructions.
After the I bit is cleared, the highest-priority interrupt request is serviced first.
A return-from-interrupt (RTI) instruction pulls the CPU registers from the stack
and restores the interrupt mask from the stack. After any reset, the interrupt
mask is set and can be cleared only by the clear interrupt mask software
instruction (CLI).
N — Negative flag
The CPU sets the negative flag when an arithmetic operation, logic operation,
or data manipulation produces a negative result, setting bit 7 of the result.
1 = Negative result
0 = Non-negative result
Z — Zero flag
The CPU sets the zero flag when an arithmetic operation, logic operation, or
data manipulation produces a result of $00.
1 = Zero result
0 = Non-zero result
C — Carry/Borrow Flag
The CPU sets the carry/borrow flag when an addition operation produces a
carry out of bit 7 of the accumulator or when a subtraction operation requires a
borrow. Some instructions — such as bit test and branch, shift, and rotate —
also clear or set the carry/borrow flag.
1 = Carry out of bit 7
0 = No carry out of bit 7
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Central Processor Unit (CPU)
67
Central Processor Unit (CPU)
7.4 Arithmetic/Logic Unit (ALU)
The ALU performs the arithmetic and logic operations defined by the instruction
set.
Refer to the CPU08 Reference Manual (Motorola document order number
CPU08RM/AD) for a description of the instructions and addressing modes and
more detail about the architecture of the CPU.
7.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby
modes.
7.5.1 Wait Mode
The WAIT instruction:
•
Clears the interrupt mask (I bit) in the condition code register, enabling
interrupts. After exit from wait mode by interrupt, the I bit remains clear. After
exit by reset, the I bit is set.
•
Disables the CPU clock
7.5.2 Stop Mode
The STOP instruction:
•
Clears the interrupt mask (I bit) in the condition code register, enabling
external interrupts. After exit from stop mode by external interrupt, the I bit
remains clear. After exit by reset, the I bit is set.
•
Disables the CPU clock
After exiting stop mode, the CPU clock begins running after the oscillator
stabilization delay.
7.6 CPU During Break Interrupts
If a break module is present on the MCU, the CPU starts a break interrupt by:
•
Loading the instruction register with the SWI instruction
•
Loading the program counter with $FFFC:$FFFD or with $FEFC:$FEFD in
monitor mode
The break interrupt begins after completion of the CPU instruction in progress. If
the break address register match occurs on the last cycle of a CPU instruction, the
break interrupt begins immediately.
A return-from-interrupt instruction (RTI) in the break routine ends the break
interrupt and returns the MCU to normal operation if the break interrupt has been
deasserted.
Data Sheet
68
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Instruction Set Summary
7.7 Instruction Set Summary
Table 7-1 provides a summary of the M68HC08 instruction set.
ADC #opr
ADC opr
ADC opr
ADC opr,X
ADC opr,X
ADC ,X
ADC opr,SP
ADC opr,SP
V H I N Z C
A ← (A) + (M) + (C)
Add with Carry
IMM
DIR
EXT
IX2
– IX1
IX
SP1
SP2
A9
B9
C9
D9
E9
F9
9EE9
9ED9
ii
dd
hh ll
ee ff
ff
IMM
DIR
EXT
IX2
– IX1
IX
SP1
SP2
AB
BB
CB
DB
EB
FB
9EEB
9EDB
ii
dd
hh ll
ee ff
ff
ff
ee ff
A7
ii
2
– – – – – – IMM
AF
ii
2
IMM
DIR
EXT
IX2
0 – – –
IX1
IX
SP1
SP2
A4
B4
C4
D4
E4
F4
9EE4
9ED4
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
0
DIR
INH
INH
– – IX1
IX
SP1
38 dd
48
58
68 ff
78
9E68 ff
4
1
1
4
3
5
C
DIR
INH
INH
– – IX1
IX
SP1
37 dd
47
57
67 ff
77
9E67 ff
4
1
1
4
3
5
Add without Carry
AIS #opr
Add Immediate Value (Signed) to SP
SP ← (SP) + (16 « M)
– – – – – – IMM
AIX #opr
Add Immediate Value (Signed) to H:X
H:X ← (H:X) + (16 « M)
A ← (A) & (M)
ASL opr
ASLA
ASLX
ASL opr,X
ASL ,X
ASL opr,SP
A ← (A) + (M)
Logical AND
Arithmetic Shift Left
(Same as LSL)
C
b7
ASR opr
ASRA
ASRX
ASR opr,X
ASR opr,X
ASR opr,SP
Arithmetic Shift Right
BCC rel
Branch if Carry Bit Clear
b0
b7
2
3
4
4
3
2
4
5
2
3
4
4
3
2
4
5
ADD #opr
ADD opr
ADD opr
ADD opr,X
ADD opr,X
ADD ,X
ADD opr,SP
ADD opr,SP
AND #opr
AND opr
AND opr
AND opr,X
AND opr,X
AND ,X
AND opr,SP
AND opr,SP
ff
ee ff
Cycles
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 1 of 7)
b0
PC ← (PC) + 2 + rel ? (C) = 0
Mn ← 0
ff
ee ff
– – – – – – REL
24
rr
3
DIR (b0)
DIR (b1)
DIR (b2)
– – – – – – DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
11
13
15
17
19
1B
1D
1F
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
BCLR n, opr
Clear Bit n in M
BCS rel
Branch if Carry Bit Set (Same as BLO)
PC ← (PC) + 2 + rel ? (C) = 1
– – – – – – REL
25
rr
3
BEQ rel
Branch if Equal
PC ← (PC) + 2 + rel ? (Z) = 1
– – – – – – REL
27
rr
3
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Central Processor Unit (CPU)
69
Central Processor Unit (CPU)
V H I N Z C
BGE opr
Branch if Greater Than or Equal To
(Signed Operands)
BGT opr
Branch if Greater Than (Signed
Operands)
BHCC rel
Branch if Half Carry Bit Clear
PC ← (PC) + 2 + rel ? (H) = 0
BHCS rel
Branch if Half Carry Bit Set
BHI rel
Branch if Higher
BHS rel
PC ← (PC) + 2 + rel ? (N ⊕ V) = 0
Cycles
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 2 of 7)
– – – – – – REL
90
rr
3
PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) = 0 – – – – – – REL
92
rr
3
– – – – – – REL
28
rr
3
PC ← (PC) + 2 + rel ? (H) = 1
– – – – – – REL
29
rr
PC ← (PC) + 2 + rel ? (C) | (Z) = 0
– – – – – – REL
22
rr
3
Branch if Higher or Same
(Same as BCC)
PC ← (PC) + 2 + rel ? (C) = 0
– – – – – – REL
24
rr
3
BIH rel
Branch if IRQ Pin High
PC ← (PC) + 2 + rel ? IRQ = 1
– – – – – – REL
2F
rr
3
BIL rel
Branch if IRQ Pin Low
PC ← (PC) + 2 + rel ? IRQ = 0
– – – – – – REL
2E
rr
3
(A) & (M)
IMM
DIR
EXT
0 – – – IX2
IX1
IX
SP1
SP2
A5
B5
C5
D5
E5
F5
9EE5
9ED5
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
93
rr
3
BIT #opr
BIT opr
BIT opr
BIT opr,X
BIT opr,X
BIT ,X
BIT opr,SP
BIT opr,SP
Bit Test
BLE opr
Branch if Less Than or Equal To
(Signed Operands)
BLO rel
Branch if Lower (Same as BCS)
BLS rel
PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) = 1 – – – – – – REL
3
PC ← (PC) + 2 + rel ? (C) = 1
– – – – – – REL
25
rr
3
Branch if Lower or Same
PC ← (PC) + 2 + rel ? (C) | (Z) = 1
– – – – – – REL
23
rr
3
BLT opr
Branch if Less Than (Signed Operands)
PC ← (PC) + 2 + rel ? (N ⊕ V) =1
– – – – – – REL
91
rr
3
BMC rel
Branch if Interrupt Mask Clear
PC ← (PC) + 2 + rel ? (I) = 0
– – – – – – REL
2C
rr
3
BMI rel
Branch if Minus
PC ← (PC) + 2 + rel ? (N) = 1
– – – – – – REL
2B
rr
3
BMS rel
Branch if Interrupt Mask Set
PC ← (PC) + 2 + rel ? (I) = 1
– – – – – – REL
2D
rr
3
BNE rel
Branch if Not Equal
PC ← (PC) + 2 + rel ? (Z) = 0
– – – – – – REL
26
rr
3
BPL rel
Branch if Plus
PC ← (PC) + 2 + rel ? (N) = 0
– – – – – – REL
2A
rr
3
BRA rel
Branch Always
PC ← (PC) + 2 + rel
– – – – – – REL
20
rr
3
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
01
03
05
07
09
0B
0D
0F
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
– – – – – – REL
21
rr
3
BRCLR n,opr,rel Branch if Bit n in M Clear
BRN rel
Branch Never
PC ← (PC) + 3 + rel ? (Mn) = 0
PC ← (PC) + 2
Data Sheet
70
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Instruction Set Summary
PC ← (PC) + 3 + rel ? (Mn) = 1
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
00
02
04
06
08
0A
0C
0E
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
Mn ← 1
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
– – – – – – DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
10
12
14
16
18
1A
1C
1E
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
PC ← (PC) + 2; push (PCL)
SP ← (SP) – 1; push (PCH)
SP ← (SP) – 1
PC ← (PC) + rel
– – – – – – REL
AD
rr
4
PC ← (PC) + 3 + rel ? (A) – (M) = $00
PC ← (PC) + 3 + rel ? (A) – (M) = $00
PC ← (PC) + 3 + rel ? (X) – (M) = $00
PC ← (PC) + 3 + rel ? (A) – (M) = $00
PC ← (PC) + 2 + rel ? (A) – (M) = $00
PC ← (PC) + 4 + rel ? (A) – (M) = $00
DIR
IMM
– – – – – – IMM
IX1+
IX+
SP1
31
41
51
61
71
9E61
dd rr
ii rr
ii rr
ff rr
rr
ff rr
5
4
4
5
4
6
Description
V H I N Z C
BRSET n,opr,rel Branch if Bit n in M Set
BSET n,opr
Set Bit n in M
BSR rel
Branch to Subroutine
CBEQ opr,rel
CBEQA #opr,rel
CBEQX #opr,rel Compare and Branch if Equal
CBEQ opr,X+,rel
CBEQ X+,rel
CBEQ opr,SP,rel
Cycles
Operand
Operation
Effect
on CCR
Address
Mode
Source
Form
Opcode
Table 7-1. Instruction Set Summary (Sheet 3 of 7)
CLC
Clear Carry Bit
C←0
– – – – – 0 INH
98
1
CLI
Clear Interrupt Mask
I←0
– – 0 – – – INH
9A
2
M ← $00
A ← $00
X ← $00
H ← $00
M ← $00
M ← $00
M ← $00
DIR
INH
INH
0 – – 0 1 – INH
IX1
IX
SP1
3F dd
4F
5F
8C
6F ff
7F
9E6F ff
(A) – (M)
IMM
DIR
EXT
IX2
– – IX1
IX
SP1
SP2
A1
B1
C1
D1
E1
F1
9EE1
9ED1
M ← (M) = $FF – (M)
A ← (A) = $FF – (M)
X ← (X) = $FF – (M)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
DIR
INH
INH
0 – – 1 IX1
IX
SP1
33 dd
43
53
63 ff
73
9E63 ff
(H:X) – (M:M + 1)
– – IMM
DIR
CLR opr
CLRA
CLRX
CLRH
CLR opr,X
CLR ,X
CLR opr,SP
CMP #opr
CMP opr
CMP opr
CMP opr,X
CMP opr,X
CMP ,X
CMP opr,SP
CMP opr,SP
Clear
Compare A with M
COM opr
COMA
COMX
COM opr,X
COM ,X
COM opr,SP
Complement (One’s Complement)
CPHX #opr
CPHX opr
Compare H:X with M
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
65
75
ii
dd
hh ll
ee ff
ff
ff
ee ff
ii ii+1
dd
3
1
1
1
3
2
4
2
3
4
4
3
2
4
5
4
1
1
4
3
5
3
4
Data Sheet
Central Processor Unit (CPU)
71
Central Processor Unit (CPU)
Compare X with M
DAA
Decimal Adjust A
DBNZ opr,rel
DBNZA rel
DBNZX rel
Decrement and Branch if Not Zero
DBNZ opr,X,rel
DBNZ X,rel
DBNZ opr,SP,rel
DEC opr
DECA
DECX
DEC opr,X
DEC ,X
DEC opr,SP
Decrement
DIV
Divide
INC opr
INCA
INCX
INC opr,X
INC ,X
INC opr,SP
JMP opr
JMP opr
JMP opr,X
JMP opr,X
JMP ,X
JSR opr
JSR opr
JSR opr,X
JSR opr,X
JSR ,X
LDA #opr
LDA opr
LDA opr
LDA opr,X
LDA opr,X
LDA ,X
LDA opr,SP
LDA opr,SP
Exclusive OR M with A
Increment
Jump
Jump to Subroutine
Load A from M
(X) – (M)
(A)10
A3
B3
C3
D3
E3
F3
9EE3
9ED3
U – – INH
72
A ← (A) – 1 or M ← (M) – 1 or X ← (X) – 1
PC ← (PC) + 3 + rel ? (result) ≠ 0
DIR
PC ← (PC) + 2 + rel ? (result) ≠ 0
INH
PC ← (PC) + 2 + rel ? (result) ≠ 0
– – – – – – INH
PC ← (PC) + 3 + rel ? (result) ≠ 0
IX1
PC ← (PC) + 2 + rel ? (result) ≠ 0
IX
PC ← (PC) + 4 + rel ? (result) ≠ 0
SP1
3B
4B
5B
6B
7B
9E6B
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
2
dd rr
rr
rr
ff rr
rr
ff rr
5
3
3
5
4
6
M ← (M) – 1
A ← (A) – 1
X ← (X) – 1
M ← (M) – 1
M ← (M) – 1
M ← (M) – 1
DIR
INH
– – – INH
IX1
IX
SP1
A ← (H:A)/(X)
H ← Remainder
– – – – INH
52
A ← (A ⊕ M)
IMM
DIR
EXT
IX2
0 – – –
IX1
IX
SP1
SP2
A8
B8
C8
D8
E8
F8
9EE8
9ED8
M ← (M) + 1
A ← (A) + 1
X ← (X) + 1
M ← (M) + 1
M ← (M) + 1
M ← (M) + 1
DIR
INH
INH
– – – IX1
IX
SP1
3C dd
4C
5C
6C ff
7C
9E6C ff
PC ← Jump Address
DIR
EXT
– – – – – – IX2
IX1
IX
BC
CC
DC
EC
FC
dd
hh ll
ee ff
ff
2
3
4
3
2
PC ← (PC) + n (n = 1, 2, or 3)
Push (PCL); SP ← (SP) – 1
Push (PCH); SP ← (SP) – 1
PC ← Unconditional Address
DIR
EXT
– – – – – – IX2
IX1
IX
BD
CD
DD
ED
FD
dd
hh ll
ee ff
ff
4
5
6
5
4
A ← (M)
IMM
DIR
EXT
0 – – – IX2
IX1
IX
SP1
SP2
A6
B6
C6
D6
E6
F6
9EE6
9ED6
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
Data Sheet
72
IMM
DIR
EXT
IX2
– – IX1
IX
SP1
SP2
Cycles
V H I N Z C
CPX #opr
CPX opr
CPX opr
CPX ,X
CPX opr,X
CPX opr,X
CPX opr,SP
CPX opr,SP
EOR #opr
EOR opr
EOR opr
EOR opr,X
EOR opr,X
EOR ,X
EOR opr,SP
EOR opr,SP
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 4 of 7)
3A dd
4A
5A
6A ff
7A
9E6A ff
4
1
1
4
3
5
7
ii
dd
hh ll
ee ff
ff
ff
ee ff
ff
ee ff
2
3
4
4
3
2
4
5
4
1
1
4
3
5
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Instruction Set Summary
LDHX #opr
LDHX opr
LDX #opr
LDX opr
LDX opr
LDX opr,X
LDX opr,X
LDX ,X
LDX opr,SP
LDX opr,SP
LSL opr
LSLA
LSLX
LSL opr,X
LSL ,X
LSL opr,SP
V H I N Z C
Load H:X from M
H:X ← (M:M + 1)
IMM
0 – – – DIR
45
55
X ← (M)
IMM
DIR
EXT
IX2
0 – – – IX1
IX
SP1
SP2
AE
BE
CE
DE
EE
FE
9EEE
9EDE
0
DIR
INH
– – INH
IX1
IX
SP1
38 dd
48
58
68 ff
78
9E68 ff
4
1
1
4
3
5
C
DIR
INH
INH
– – 0 IX1
IX
SP1
34 dd
44
54
64 ff
74
9E64 ff
4
1
1
4
3
5
Load X from M
Logical Shift Left
(Same as ASL)
LSR opr
LSRA
LSRX
LSR opr,X
LSR ,X
LSR opr,SP
Logical Shift Right
MOV opr,opr
MOV opr,X+
MOV #opr,opr
MOV X+,opr
Move
MUL
Unsigned multiply
Cycles
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 5 of 7)
C
b7
b0
0
b7
b0
(M)Destination ← (M)Source
H:X ← (H:X) + 1 (IX+D, DIX+)
0 – – –
DD
DIX+
IMD
IX+D
X:A ← (X) × (A)
– 0 – – – 0 INH
M ← –(M) = $00 – (M)
A ← –(A) = $00 – (A)
X ← –(X) = $00 – (X)
M ← –(M) = $00 – (M)
M ← –(M) = $00 – (M)
DIR
INH
INH
– – IX1
IX
SP1
4E
5E
6E
7E
ii jj
dd
3
4
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
ff
ee ff
dd dd
dd
ii dd
dd
42
5
4
4
4
5
30 dd
40
50
60 ff
70
9E60 ff
4
1
1
4
3
5
NEG opr
NEGA
NEGX
NEG opr,X
NEG ,X
NEG opr,SP
Negate (Two’s Complement)
NOP
No Operation
None
– – – – – – INH
9D
1
NSA
Nibble Swap A
A ← (A[3:0]:A[7:4])
– – – – – – INH
62
3
A ← (A) | (M)
IMM
DIR
EXT
IX2
0 – – – IX1
IX
SP1
SP2
AA
BA
CA
DA
EA
FA
9EEA
9EDA
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
ORA #opr
ORA opr
ORA opr
ORA opr,X
ORA opr,X
ORA ,X
ORA opr,SP
ORA opr,SP
Inclusive OR A and M
PSHA
Push A onto Stack
Push (A); SP ← (SP) – 1
– – – – – – INH
87
2
PSHH
Push H onto Stack
Push (H); SP ← (SP) – 1
– – – – – – INH
8B
2
PSHX
Push X onto Stack
Push (X); SP ← (SP) – 1
– – – – – – INH
89
2
PULA
Pull A from Stack
SP ← (SP + 1); Pull (A)
– – – – – – INH
86
2
PULH
Pull H from Stack
SP ← (SP + 1); Pull (H)
– – – – – – INH
8A
2
PULX
Pull X from Stack
SP ← (SP + 1); Pull (X)
– – – – – – INH
88
2
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
ff
ee ff
Data Sheet
Central Processor Unit (CPU)
73
Central Processor Unit (CPU)
ROL opr
ROLA
ROLX
ROL opr,X
ROL ,X
ROL opr,SP
V H I N Z C
Rotate Left through Carry
C
b7
b0
Cycles
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 6 of 7)
DIR
INH
– – INH
IX1
IX
SP1
39 dd
49
59
69 ff
79
9E69 ff
4
1
1
4
3
5
DIR
INH
INH
– – IX1
IX
SP1
36 dd
46
56
66 ff
76
9E66 ff
4
1
1
4
3
5
ROR opr
RORA
RORX
ROR opr,X
ROR ,X
ROR opr,SP
Rotate Right through Carry
RSP
Reset Stack Pointer
SP ← $FF
– – – – – – INH
9C
1
RTI
Return from Interrupt
SP ← (SP) + 1; Pull (CCR)
SP ← (SP) + 1; Pull (A)
SP ← (SP) + 1; Pull (X)
SP ← (SP) + 1; Pull (PCH)
SP ← (SP) + 1; Pull (PCL)
INH
80
7
RTS
Return from Subroutine
SP ← SP + 1; Pull (PCH)
SP ← SP + 1; Pull (PCL)
– – – – – – INH
81
4
A ← (A) – (M) – (C)
IMM
DIR
EXT
– – IX2
IX1
IX
SP1
SP2
A2
B2
C2
D2
E2
F2
9EE2
9ED2
C
b7
b0
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
2
4
5
SBC #opr
SBC opr
SBC opr
SBC opr,X
SBC opr,X
SBC ,X
SBC opr,SP
SBC opr,SP
Subtract with Carry
SEC
Set Carry Bit
C←1
– – – – – 1 INH
99
1
SEI
Set Interrupt Mask
I←1
– – 1 – – – INH
9B
2
M ← (A)
DIR
EXT
IX2
0 – – – IX1
IX
SP1
SP2
B7
C7
D7
E7
F7
9EE7
9ED7
(M:M + 1) ← (H:X)
0 – – – DIR
35
I ← 0; Stop Oscillator
– – 0 – – – INH
8E
M ← (X)
DIR
EXT
IX2
0 – – – IX1
IX
SP1
SP2
BF
CF
DF
EF
FF
9EEF
9EDF
dd
hh ll
ee ff
ff
IMM
DIR
EXT
– – IX2
IX1
IX
SP1
SP2
A0
B0
C0
D0
E0
F0
9EE0
9ED0
ii
dd
hh ll
ee ff
ff
STA opr
STA opr
STA opr,X
STA opr,X
STA ,X
STA opr,SP
STA opr,SP
Store A in M
STHX opr
Store H:X in M
STOP
Enable IRQ Pin; Stop Oscillator
STX opr
STX opr
STX opr,X
STX opr,X
STX ,X
STX opr,SP
STX opr,SP
SUB #opr
SUB opr
SUB opr
SUB opr,X
SUB opr,X
SUB ,X
SUB opr,SP
SUB opr,SP
Store X in M
Subtract
A ← (A) – (M)
Data Sheet
74
ff
ee ff
dd
hh ll
ee ff
ff
ff
ee ff
3
4
4
3
2
4
5
dd
4
1
ff
ee ff
ff
ee ff
3
4
4
3
2
4
5
2
3
4
4
3
2
4
5
MC68HC908QY/QT Family — Rev. 3
Central Processor Unit (CPU)
MOTOROLA
Central Processor Unit (CPU)
Opcode Map
V H I N Z C
Cycles
Description
Operand
Operation
Effect
on CCR
Opcode
Source
Form
Address
Mode
Table 7-1. Instruction Set Summary (Sheet 7 of 7)
SWI
Software Interrupt
PC ← (PC) + 1; Push (PCL)
SP ← (SP) – 1; Push (PCH)
SP ← (SP) – 1; Push (X)
SP ← (SP) – 1; Push (A)
SP ← (SP) – 1; Push (CCR)
SP ← (SP) – 1; I ← 1
PCH ← Interrupt Vector High Byte
PCL ← Interrupt Vector Low Byte
TAP
Transfer A to CCR
CCR ← (A)
INH
84
2
TAX
Transfer A to X
X ← (A)
– – – – – – INH
97
1
TPA
Transfer CCR to A
A ← (CCR)
– – – – – – INH
85
1
(A) – $00 or (X) – $00 or (M) – $00
DIR
INH
0 – – – INH
IX1
IX
SP1
H:X ← (SP) + 1
– – – – – – INH
95
2
A ← (X)
– – – – – – INH
9F
1
(SP) ← (H:X) – 1
– – – – – – INH
94
2
TST opr
TSTA
TSTX
TST opr,X
TST ,X
TST opr,SP
Test for Negative or Zero
TSX
Transfer SP to H:X
TXA
Transfer X to A
TXS
Transfer H:X to SP
A
C
CCR
dd
dd rr
DD
DIR
DIX+
ee ff
EXT
ff
H
H
hh ll
I
ii
IMD
IMM
INH
IX
IX+
IX+D
IX1
IX1+
IX2
M
N
Accumulator
Carry/borrow bit
Condition code register
Direct address of operand
Direct address of operand and relative offset of branch instruction
Direct to direct addressing mode
Direct addressing mode
Direct to indexed with post increment addressing mode
High and low bytes of offset in indexed, 16-bit offset addressing
Extended addressing mode
Offset byte in indexed, 8-bit offset addressing
Half-carry bit
Index register high byte
High and low bytes of operand address in extended addressing
Interrupt mask
Immediate operand byte
Immediate source to direct destination addressing mode
Immediate addressing mode
Inherent addressing mode
Indexed, no offset addressing mode
Indexed, no offset, post increment addressing mode
Indexed with post increment to direct addressing mode
Indexed, 8-bit offset addressing mode
Indexed, 8-bit offset, post increment addressing mode
Indexed, 16-bit offset addressing mode
Memory location
Negative bit
n
opr
PC
PCH
PCL
REL
rel
rr
SP1
SP2
SP
U
V
X
Z
&
|
⊕
()
–( )
#
«
←
?
:
—
– – 1 – – – INH
83
9
3D dd
4D
5D
6D ff
7D
9E6D ff
3
1
1
3
2
4
Any bit
Operand (one or two bytes)
Program counter
Program counter high byte
Program counter low byte
Relative addressing mode
Relative program counter offset byte
Relative program counter offset byte
Stack pointer, 8-bit offset addressing mode
Stack pointer 16-bit offset addressing mode
Stack pointer
Undefined
Overflow bit
Index register low byte
Zero bit
Logical AND
Logical OR
Logical EXCLUSIVE OR
Contents of
Negation (two’s complement)
Immediate value
Sign extend
Loaded with
If
Concatenated with
Set or cleared
Not affected
7.8 Opcode Map
See Table 7-2.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Central Processor Unit (CPU)
75
MSB
Branch
REL
DIR
INH
3
4
0
1
2
5
BRSET0
3 DIR
5
BRCLR0
3 DIR
5
BRSET1
3 DIR
5
BRCLR1
3 DIR
5
BRSET2
3 DIR
5
BRCLR2
3 DIR
5
BRSET3
3 DIR
5
BRCLR3
3 DIR
5
BRSET4
3 DIR
5
BRCLR4
3 DIR
5
BRSET5
3 DIR
5
BRCLR5
3 DIR
5
BRSET6
3 DIR
5
BRCLR6
3 DIR
5
BRSET7
3 DIR
5
BRCLR7
3 DIR
4
BSET0
2 DIR
4
BCLR0
2 DIR
4
BSET1
2 DIR
4
BCLR1
2 DIR
4
BSET2
2 DIR
4
BCLR2
2 DIR
4
BSET3
2 DIR
4
BCLR3
2 DIR
4
BSET4
2 DIR
4
BCLR4
2 DIR
4
BSET5
2 DIR
4
BCLR5
2 DIR
4
BSET6
2 DIR
4
BCLR6
2 DIR
4
BSET7
2 DIR
4
BCLR7
2 DIR
3
BRA
2 REL
3
BRN
2 REL
3
BHI
2 REL
3
BLS
2 REL
3
BCC
2 REL
3
BCS
2 REL
3
BNE
2 REL
3
BEQ
2 REL
3
BHCC
2 REL
3
BHCS
2 REL
3
BPL
2 REL
3
BMI
2 REL
3
BMC
2 REL
3
BMS
2 REL
3
BIL
2 REL
3
BIH
2 REL
Read-Modify-Write
INH
IX1
5
6
1
NEGX
1 INH
4
CBEQX
3 IMM
7
DIV
1 INH
1
COMX
1 INH
1
LSRX
1 INH
4
LDHX
2 DIR
1
RORX
1 INH
1
ASRX
1 INH
1
LSLX
1 INH
1
ROLX
1 INH
1
DECX
1 INH
3
DBNZX
2 INH
1
INCX
1 INH
1
TSTX
1 INH
4
MOV
2 DIX+
1
CLRX
1 INH
4
NEG
2
IX1
5
CBEQ
3 IX1+
3
NSA
1 INH
4
COM
2 IX1
4
LSR
2 IX1
3
CPHX
3 IMM
4
ROR
2 IX1
4
ASR
2 IX1
4
LSL
2 IX1
4
ROL
2 IX1
4
DEC
2 IX1
5
DBNZ
3 IX1
4
INC
2 IX1
3
TST
2 IX1
4
MOV
3 IMD
3
CLR
2 IX1
SP1
IX
9E6
7
Control
INH
INH
8
9
Register/Memory
IX2
SP2
IMM
DIR
EXT
A
B
C
D
9ED
4
SUB
3 EXT
4
CMP
3 EXT
4
SBC
3 EXT
4
CPX
3 EXT
4
AND
3 EXT
4
BIT
3 EXT
4
LDA
3 EXT
4
STA
3 EXT
4
EOR
3 EXT
4
ADC
3 EXT
4
ORA
3 EXT
4
ADD
3 EXT
3
JMP
3 EXT
5
JSR
3 EXT
4
LDX
3 EXT
4
STX
3 EXT
4
SUB
3 IX2
4
CMP
3 IX2
4
SBC
3 IX2
4
CPX
3 IX2
4
AND
3 IX2
4
BIT
3 IX2
4
LDA
3 IX2
4
STA
3 IX2
4
EOR
3 IX2
4
ADC
3 IX2
4
ORA
3 IX2
4
ADD
3 IX2
4
JMP
3 IX2
6
JSR
3 IX2
4
LDX
3 IX2
4
STX
3 IX2
5
SUB
4 SP2
5
CMP
4 SP2
5
SBC
4 SP2
5
CPX
4 SP2
5
AND
4 SP2
5
BIT
4 SP2
5
LDA
4 SP2
5
STA
4 SP2
5
EOR
4 SP2
5
ADC
4 SP2
5
ORA
4 SP2
5
ADD
4 SP2
IX1
SP1
IX
E
9EE
F
LSB
0
1
2
3
4
5
Central Processor Unit (CPU)
6
7
8
9
A
B
C
MOTOROLA
MC68HC908QY/QT Family — Rev. 3
D
E
F
4
1
NEG
NEGA
2 DIR 1 INH
5
4
CBEQ CBEQA
3 DIR 3 IMM
5
MUL
1 INH
4
1
COM
COMA
2 DIR 1 INH
4
1
LSR
LSRA
2 DIR 1 INH
4
3
STHX
LDHX
2 DIR 3 IMM
4
1
ROR
RORA
2 DIR 1 INH
4
1
ASR
ASRA
2 DIR 1 INH
4
1
LSL
LSLA
2 DIR 1 INH
4
1
ROL
ROLA
2 DIR 1 INH
4
1
DEC
DECA
2 DIR 1 INH
5
3
DBNZ DBNZA
3 DIR 2 INH
4
1
INC
INCA
2 DIR 1 INH
3
1
TST
TSTA
2 DIR 1 INH
5
MOV
3 DD
3
1
CLR
CLRA
2 DIR 1 INH
INH Inherent
REL Relative
IMM Immediate
IX
Indexed, No Offset
DIR Direct
IX1 Indexed, 8-Bit Offset
EXT Extended
IX2 Indexed, 16-Bit Offset
DD Direct-Direct
IMD Immediate-Direct
IX+D Indexed-Direct DIX+ Direct-Indexed
*Pre-byte for stack pointer indexed instructions
5
3
NEG
NEG
3 SP1 1 IX
6
4
CBEQ
CBEQ
4 SP1 2 IX+
2
DAA
1 INH
5
3
COM
COM
3 SP1 1 IX
5
3
LSR
LSR
3 SP1 1 IX
4
CPHX
2 DIR
5
3
ROR
ROR
3 SP1 1 IX
5
3
ASR
ASR
3 SP1 1 IX
5
3
LSL
LSL
3 SP1 1 IX
5
3
ROL
ROL
3 SP1 1 IX
5
3
DEC
DEC
3 SP1 1 IX
6
4
DBNZ
DBNZ
4 SP1 2 IX
5
3
INC
INC
3 SP1 1 IX
4
2
TST
TST
3 SP1 1 IX
4
MOV
2 IX+D
4
2
CLR
CLR
3 SP1 1 IX
SP1 Stack Pointer, 8-Bit Offset
SP2 Stack Pointer, 16-Bit Offset
IX+ Indexed, No Offset with
Post Increment
IX1+ Indexed, 1-Byte Offset with
Post Increment
7
3
RTI
BGE
1 INH 2 REL
4
3
RTS
BLT
1 INH 2 REL
3
BGT
2 REL
9
3
SWI
BLE
1 INH 2 REL
2
2
TAP
TXS
1 INH 1 INH
1
2
TPA
TSX
1 INH 1 INH
2
PULA
1 INH
2
1
PSHA
TAX
1 INH 1 INH
2
1
PULX
CLC
1 INH 1 INH
2
1
PSHX
SEC
1 INH 1 INH
2
2
PULH
CLI
1 INH 1 INH
2
2
PSHH
SEI
1 INH 1 INH
1
1
CLRH
RSP
1 INH 1 INH
1
NOP
1 INH
1
STOP
*
1 INH
1
1
WAIT
TXA
1 INH 1 INH
2
SUB
2 IMM
2
CMP
2 IMM
2
SBC
2 IMM
2
CPX
2 IMM
2
AND
2 IMM
2
BIT
2 IMM
2
LDA
2 IMM
2
AIS
2 IMM
2
EOR
2 IMM
2
ADC
2 IMM
2
ORA
2 IMM
2
ADD
2 IMM
3
SUB
2 DIR
3
CMP
2 DIR
3
SBC
2 DIR
3
CPX
2 DIR
3
AND
2 DIR
3
BIT
2 DIR
3
LDA
2 DIR
3
STA
2 DIR
3
EOR
2 DIR
3
ADC
2 DIR
3
ORA
2 DIR
3
ADD
2 DIR
2
JMP
2 DIR
4
4
BSR
JSR
2 REL 2 DIR
2
3
LDX
LDX
2 IMM 2 DIR
2
3
AIX
STX
2 IMM 2 DIR
MSB
0
3
SUB
2 IX1
3
CMP
2 IX1
3
SBC
2 IX1
3
CPX
2 IX1
3
AND
2 IX1
3
BIT
2 IX1
3
LDA
2 IX1
3
STA
2 IX1
3
EOR
2 IX1
3
ADC
2 IX1
3
ORA
2 IX1
3
ADD
2 IX1
3
JMP
2 IX1
5
JSR
2 IX1
5
3
LDX
LDX
4 SP2 2 IX1
5
3
STX
STX
4 SP2 2 IX1
4
SUB
3 SP1
4
CMP
3 SP1
4
SBC
3 SP1
4
CPX
3 SP1
4
AND
3 SP1
4
BIT
3 SP1
4
LDA
3 SP1
4
STA
3 SP1
4
EOR
3 SP1
4
ADC
3 SP1
4
ORA
3 SP1
4
ADD
3 SP1
2
SUB
1 IX
2
CMP
1 IX
2
SBC
1 IX
2
CPX
1 IX
2
AND
1 IX
2
BIT
1 IX
2
LDA
1 IX
2
STA
1 IX
2
EOR
1 IX
2
ADC
1 IX
2
ORA
1 IX
2
ADD
1 IX
2
JMP
1 IX
4
JSR
1 IX
4
2
LDX
LDX
3 SP1 1 IX
4
2
STX
STX
3 SP1 1 IX
High Byte of Opcode in Hexadecimal
LSB
Low Byte of Opcode in Hexadecimal
0
5
Cycles
BRSET0 Opcode Mnemonic
3 DIR Number of Bytes / Addressing Mode
Central Processor Unit (CPU)
Data Sheet
76
Table 7-2. Opcode Map
Bit Manipulation
DIR
DIR
Data Sheet — MC68HC908QY/QT Family
Section 8. External Interrupt (IRQ)
8.1 Introduction
The IRQ pin (external interrupt), shared with PTA2 (general purpose input) and
keyboard interrupt (KBI), provides a maskable interrupt input
8.2 Features
Features of the IRQ module include the following:
•
External interrupt pin, IRQ
•
IRQ interrupt control bits
•
Hysteresis buffer
•
Programmable edge-only or edge and level interrupt sensitivity
•
Automatic interrupt acknowledge
•
Selectable internal pullup resistor
8.3 Functional Description
IRQ pin functionality is enabled by setting configuration register 2 (CONFIG2)
IRQEN bit accordingly. A zero disables the IRQ function and IRQ will assume the
other shared functionalities. A one enables the IRQ function.
A falling edge on the external interrupt pin can latch a central processor unit (CPU)
interrupt request. Figure 8-2 shows the structure of the IRQ module.
Interrupt signals on the IRQ pin are latched into the IRQ latch. An interrupt latch
remains set until one of the following actions occurs:
•
Vector fetch — A vector fetch automatically generates an interrupt
acknowledge signal that clears the IRQ latch.
•
Software clear — Software can clear the interrupt latch by writing to the
acknowledge bit in the interrupt status and control register (INTSCR).
Writing a 1 to the ACK bit clears the IRQ latch.
•
Reset — A reset automatically clears the interrupt latch.
The external interrupt pin is falling-edge-triggered out of reset and is softwareconfigurable to be either falling-edge or falling-edge and low-level triggered. The
MODE bit in the INTSCR controls the triggering sensitivity of the IRQ pin.
When the interrupt pin is edge-triggered only (MODE = 0), the CPU interrupt
request remains set until a vector fetch, software clear, or reset occurs.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
External Interrupt (IRQ)
77
External Interrupt (IRQ)
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 8-1. Block Diagram Highlighting IRQ Block and Pins
Data Sheet
78
MC68HC908QY/QT Family — Rev. 3
External Interrupt (IRQ)
MOTOROLA
External Interrupt (IRQ)
Functional Description
ACK
INTERNAL ADDRESS BUS
RESET
TO CPU FOR
BIL/BIH
INSTRUCTIONS
VECTOR
FETCH
DECODER
VDD
IRQPUD
INTERNAL
PULLUP
DEVICE
VDD
IRQF
D
CLR
Q
CK
IRQ
SYNCHRONIZER
IRQ
INTERRUPT
REQUEST
HIGH
VOLTAGE
DETECT
TO MODE
SELECT
LOGIC
IRQ
FF
IMASK
MODE
Figure 8-2. IRQ Module Block Diagram
When the interrupt pin is both falling-edge and low-level triggered (MODE = 1), the
CPU interrupt request remains set until both of the following occur:
•
Vector fetch or software clear
•
Return of the interrupt pin to logic 1
The vector fetch or software clear may occur before or after the interrupt pin returns
to logic 1. As long as the pin is low, the interrupt request remains pending. A reset
will clear the latch and the MODE control bit, thereby clearing the interrupt even if
the pin stays low.
When set, the IMASK bit in the INTSCR mask all external interrupt requests. A
latched interrupt request is not presented to the interrupt priority logic unless the
IMASK bit is clear.
NOTE:
The interrupt mask (I) in the condition code register (CCR) masks all interrupt
requests, including external interrupt requests. See 13.6 Exception Control.
Figure 8-3 provides a summary of the IRQ I/O register.
Addr.
Register Name
$001D
IRQ Status and Control Read:
Register (INTSCR) Write:
See page 81. Reset:
Bit 7
6
5
4
3
2
0
0
0
0
IRQF
0
ACK
0
0
0
0
0
0
1
Bit 0
IMASK
MODE
0
0
= Unimplemented
Figure 8-3. IRQ I/O Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
External Interrupt (IRQ)
79
External Interrupt (IRQ)
8.4 IRQ Pin
A falling edge on the IRQ pin can latch an interrupt request into the IRQ latch. A
vector fetch, software clear, or reset clears the IRQ latch.
If the MODE bit is set, the IRQ pin is both falling-edge sensitive and low-level
sensitive. With MODE set, both of the following actions must occur to clear IRQ:
•
Vector fetch or software clear — A vector fetch generates an interrupt
acknowledge signal to clear the latch. Software may generate the interrupt
acknowledge signal by writing a 1 to the ACK bit in the interrupt status and
control register (INTSCR). The ACK bit is useful in applications that poll the
IRQ pin and require software to clear the IRQ latch. Writing to the ACK bit
prior to leaving an interrupt service routine can also prevent spurious
interrupts due to noise. Setting ACK does not affect subsequent transitions
on the IRQ pin. A falling edge that occurs after writing to the ACK bit latches
another interrupt request. If the IRQ mask bit, IMASK, is clear, the CPU
loads the program counter with the vector address at locations $FFFA and
$FFFB.
•
Return of the IRQ pin to logic 1 — As long as the IRQ pin is at logic 0, IRQ
remains active.
The vector fetch or software clear and the return of the IRQ pin to logic 1 may occur
in any order. The interrupt request remains pending as long as the IRQ pin is at
logic 0. A reset will clear the latch and the MODE control bit, thereby clearing the
interrupt even if the pin stays low.
If the MODE bit is clear, the IRQ pin is falling-edge sensitive only. With MODE
clear, a vector fetch or software clear immediately clears the IRQ latch.
The IRQF bit in the INTSCR register can be used to check for pending interrupts.
The IRQF bit is not affected by the IMASK bit, which makes it useful in applications
where polling is preferred.
NOTE:
When the IRQ function is enabled in the CONFIG2 register, the BIH and BIL
instructions can be used to read the logic level on the IRQ pin. If the IRQ function
is disabled, these instructions will behave as if the IRQ pin is a logic 1, regardless
of the actual level on the pin. Conversely, when the IRQ function is enabled, bit 2
of the port A data register will always read a 0.
NOTE:
When using the level-sensitive interrupt trigger, avoid false interrupts by masking
interrupt requests in the interrupt routine. An internal pullup resistor to VDD is
connected to the IRQ pin; this can be disabled by setting the IRQPUD bit in the
CONFIG2 register ($001E).
Data Sheet
80
MC68HC908QY/QT Family — Rev. 3
External Interrupt (IRQ)
MOTOROLA
External Interrupt (IRQ)
IRQ Module During Break Interrupts
8.5 IRQ Module During Break Interrupts
The system integration module (SIM) controls whether the IRQ latch can be
cleared during the break state. The BCFE bit in the break flag control
register (BFCR) enables software to clear the latches during the break state. See
Section 13. System Integration Module (SIM).
To allow software to clear the IRQ latch during a break interrupt, write a 1 to the
BCFE bit. If a latch is cleared during the break state, it remains cleared when the
MCU exits the break state.
To protect the latches during the break state, write a 0 to the BCFE bit. With BCFE
at 0 (its default state), writing to the ACK bit in the IRQ status and control register
during the break state has no effect on the IRQ latch.
8.6 IRQ Status and Control Register
The IRQ status and control register (ISCR) controls and monitors operation of the
IRQ module, see Section 5. Configuration Register (CONFIG).
The ISCR has the following functions:
•
Shows the state of the IRQ flag
•
Clears the IRQ latch
•
Masks IRQ and interrupt request
•
Controls triggering sensitivity of the IRQ interrupt pin
Address: $001D
Read:
Bit 7
6
5
4
3
0
0
0
0
IRQF
Write:
Reset:
2
0
ACK
0
0
0
0
0
0
1
Bit 0
IMASK
MODE
0
0
= Unimplemented
Figure 8-4. IRQ Status and Control Register (INTSCR)
IRQF — IRQ Flag
This read-only status bit is high when the IRQ interrupt is pending.
1 = IRQ interrupt pending
0 = IRQ interrupt not pending
ACK — IRQ Interrupt Request Acknowledge Bit
Writing a 1 to this write-only bit clears the IRQ latch. ACK always reads as 0.
Reset clears ACK.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
External Interrupt (IRQ)
81
External Interrupt (IRQ)
IMASK — IRQ Interrupt Mask Bit
Writing a 1 to this read/write bit disables IRQ interrupt requests. Reset clears
IMASK.
1 = IRQ interrupt requests disabled
0 = IRQ interrupt requests enabled
MODE — IRQ Edge/Level Select Bit
This read/write bit controls the triggering sensitivity of the IRQ pin. Reset clears
MODE.
1 = IRQ interrupt requests on falling edges and low levels
0 = IRQ interrupt requests on falling edges only
Data Sheet
82
MC68HC908QY/QT Family — Rev. 3
External Interrupt (IRQ)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 9. Keyboard Interrupt Module (KBI)
9.1 Introduction
The keyboard interrupt module (KBI) provides six independently maskable external
interrupts, which are accessible via the PTA0–PTA5 pins.
9.2 Features
Features of the keyboard interrupt module include:
•
Six keyboard interrupt pins with separate keyboard interrupt enable bits and
one keyboard interrupt mask
•
Software configurable pullup device if input pin is configured as input port bit
•
Programmable edge-only or edge and level interrupt sensitivity
•
Exit from low-power modes
Figure 9-1 provides a summary of the input/output (I/O) registers
Addr.
Register Name
Bit 7
6
5
4
3
2
Read:
Keyboard Status and Control
$001A
Register (KBSCR) Write:
See page 88.
Reset:
0
0
0
0
KEYF
0
$001B
Read:
Keyboard Interrupt Enable
Register (KBIER) Write:
See page 89.
Reset:
1
Bit 0
IMASKK
MODEK
ACKK
0
0
0
0
0
0
0
0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
0
0
0
0
0
0
0
0
0
= Unimplemented
Figure 9-1. KBI I/O Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Keyboard Interrupt Module (KBI)
83
Keyboard Interrupt Module (KBI)
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HLC908QT1, MC68HLC908QT2, and MC68HLC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 9-2. Block Diagram Highlighting KBI Block and Pins
Data Sheet
84
MC68HC908QY/QT Family — Rev. 3
Keyboard Interrupt Module (KBI)
MOTOROLA
Keyboard Interrupt Module (KBI)
Functional Description
9.3 Functional Description
The keyboard interrupt module controls the enabling/disabling of interrupt
functions on the six port A pins. These six pins can be enabled/disabled
independently of each other.
INTERNAL BUS
VECTOR FETCH
DECODER
ACKK
KBI0
VDD
KBIE0
TO PULLUP ENABLE
.
.
.
RESET
D
CLR
KEYF
Q
SYNCHRONIZER
CK
KBI5
KEYBOARD
INTERRUPT FF
IMASKK
KEYBOARD
INTERRUPT
REQUEST
MODEK
KBIE5
TO PULLUP ENABLE
AWUIREQ(1)
1. For AWUGEN logic refer to Figure 4-2. Auto Wakeup Interrupt Request Generation Logic.
Figure 9-3. Keyboard Interrupt Block Diagram
9.3.1 Keyboard Operation
Writing to the KBIE0–KBIE5 bits in the keyboard interrupt enable register (KBIER)
independently enables or disables each port A pin as a keyboard interrupt pin.
Enabling a keyboard interrupt pin in port A also enables its internal pullup device
irrespective of PTAPUEx bits in the port A input pullup enable register (see 12.2.3
Port A Input Pullup Enable Register). A logic 0 applied to an enabled keyboard
interrupt pin latches a keyboard interrupt request.
A keyboard interrupt is latched when one or more keyboard interrupt inputs goes
low after all were high. The MODEK bit in the keyboard status and control register
controls the triggering mode of the keyboard interrupt.
•
If the keyboard interrupt is edge-sensitive only, a falling edge on a keyboard
interrupt input does not latch an interrupt request if another keyboard pin is
already low. To prevent losing an interrupt request on one input because
another input is still low, software can disable the latter input while it is low.
•
If the keyboard interrupt is falling edge and low-level sensitive, an interrupt
request is present as long as any keyboard interrupt input is low.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Keyboard Interrupt Module (KBI)
85
Keyboard Interrupt Module (KBI)
If the MODEK bit is set, the keyboard interrupt inputs are both falling edge and
low-level sensitive, and both of the following actions must occur to clear a keyboard
interrupt request:
•
Vector fetch or software clear — A vector fetch generates an interrupt
acknowledge signal to clear the interrupt request. Software may generate
the interrupt acknowledge signal by writing a 1 to the ACKK bit in the
keyboard status and control register (KBSCR). The ACKK bit is useful in
applications that poll the keyboard interrupt inputs and require software to
clear the keyboard interrupt request. Writing to the ACKK bit prior to leaving
an interrupt service routine can also prevent spurious interrupts due to
noise. Setting ACKK does not affect subsequent transitions on the keyboard
interrupt inputs. A falling edge that occurs after writing to the ACKK bit
latches another interrupt request. If the keyboard interrupt mask bit,
IMASKK, is clear, the central processor unit (CPU) loads the program
counter with the vector address at locations $FFE0 and $FFE1.
•
Return of all enabled keyboard interrupt inputs to logic 1 — As long as any
enabled keyboard interrupt pin is at logic 0, the keyboard interrupt remains
set. The auto wakeup interrupt input, AWUIREQ, will be cleared only by
writing to ACKK bit in KBSCR or reset.
The vector fetch or software clear and the return of all enabled keyboard interrupt
pins to logic 1 may occur in any order.
If the MODEK bit is clear, the keyboard interrupt pin is falling-edge sensitive only.
With MODEK clear, a vector fetch or software clear immediately clears the
keyboard interrupt request.
Reset clears the keyboard interrupt request and the MODEK bit, clearing the
interrupt request even if a keyboard interrupt input stays at logic 0.
The keyboard flag bit (KEYF) in the keyboard status and control register can be
used to see if a pending interrupt exists. The KEYF bit is not affected by the
keyboard interrupt mask bit (IMASKK) which makes it useful in applications where
polling is preferred.
To determine the logic level on a keyboard interrupt pin, use the data direction
register to configure the pin as an input and then read the data register.
NOTE:
Setting a keyboard interrupt enable bit (KBIEx) forces the corresponding keyboard
interrupt pin to be an input, overriding the data direction register. However, the data
direction register bit must be a 0 for software to read the pin.
Data Sheet
86
MC68HC908QY/QT Family — Rev. 3
Keyboard Interrupt Module (KBI)
MOTOROLA
Keyboard Interrupt Module (KBI)
Wait Mode
9.3.2 Keyboard Initialization
When a keyboard interrupt pin is enabled, it takes time for the internal pullup to
reach a logic 1. Therefore a false interrupt can occur as soon as the pin is enabled.
To prevent a false interrupt on keyboard initialization:
1. Mask keyboard interrupts by setting the IMASKK bit in the keyboard status
and control register.
2. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard
interrupt enable register.
3. Write to the ACKK bit in the keyboard status and control register to clear any
false interrupts.
4. Clear the IMASKK bit.
An interrupt signal on an edge-triggered pin can be acknowledged immediately
after enabling the pin. An interrupt signal on an edge- and level-triggered interrupt
pin must be acknowledged after a delay that depends on the external load.
Another way to avoid a false interrupt:
1. Configure the keyboard pins as outputs by setting the appropriate DDRA
bits in the data direction register A.
2. Write 1s to the appropriate port A data register bits.
3. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard
interrupt enable register.
9.4 Wait Mode
The keyboard module remains active in wait mode. Clearing the IMASKK bit in the
keyboard status and control register enables keyboard interrupt requests to bring
the MCU out of wait mode.
9.5 Stop Mode
The keyboard module remains active in stop mode. Clearing the IMASKK bit in the
keyboard status and control register enables keyboard interrupt requests to bring
the MCU out of stop mode.
9.6 Keyboard Module During Break Interrupts
The system integration module (SIM) controls whether the keyboard interrupt latch
can be cleared during the break state. The BCFE bit in the break flag control
register (BFCR) enables software to clear status bits during the break state.
To allow software to clear the keyboard interrupt latch during a break interrupt,
write a 1 to the BCFE bit. If a latch is cleared during the break state, it remains
cleared when the MCU exits the break state.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Keyboard Interrupt Module (KBI)
87
Keyboard Interrupt Module (KBI)
To protect the latch during the break state, write a 0 to the BCFE bit. With BCFE
at 0 (its default state), writing to the keyboard acknowledge bit (ACKK) in the
keyboard status and control register during the break state has no effect.
9.7 Input/Output Registers
The following I/O registers control and monitor operation of the keyboard interrupt
module:
•
Keyboard interrupt status and control register (KBSCR)
•
Keyboard interrupt enable register (KBIER)
9.7.1 Keyboard Status and Control Register
The keyboard status and control register (KBSCR):
•
Flags keyboard interrupt requests
•
Acknowledges keyboard interrupt requests
•
Masks keyboard interrupt requests
•
Controls keyboard interrupt triggering sensitivity
Address: $001A
Read:
Bit 7
6
5
4
3
2
0
0
0
0
KEYF
0
Write:
Reset:
ACKK
0
0
0
0
0
0
1
Bit 0
IMASKK
MODEK
0
0
= Unimplemented
Figure 9-4. Keyboard Status and Control Register (KBSCR)
Bits 7–4 — Not used
These read-only bits always read as 0s.
KEYF — Keyboard Flag Bit
This read-only bit is set when a keyboard interrupt is pending on port A or auto
wakeup. Reset clears the KEYF bit.
1 = Keyboard interrupt pending
0 = No keyboard interrupt pending
ACKK — Keyboard Acknowledge Bit
Writing a 1 to this write-only bit clears the keyboard interrupt request on port A
and auto wakeup logic. ACKK always reads as 0. Reset clears ACKK.
IMASKK— Keyboard Interrupt Mask Bit
Writing a 1 to this read/write bit prevents the output of the keyboard interrupt
mask from generating interrupt requests on port A or auto wakeup. Reset clears
the IMASKK bit.
1 = Keyboard interrupt requests masked
0 = Keyboard interrupt requests not masked
Data Sheet
88
MC68HC908QY/QT Family — Rev. 3
Keyboard Interrupt Module (KBI)
MOTOROLA
Keyboard Interrupt Module (KBI)
Input/Output Registers
MODEK — Keyboard Triggering Sensitivity Bit
This read/write bit controls the triggering sensitivity of the keyboard interrupt
pins on port A and auto wakeup. Reset clears MODEK.
1 = Keyboard interrupt requests on falling edges and low levels
0 = Keyboard interrupt requests on falling edges only
9.7.2 Keyboard Interrupt Enable Register
The port A keyboard interrupt enable register (KBIER) enables or disables each
port A pin or auto wakeup to operate as a keyboard interrupt input.
Address: $001B
Bit 7
Read:
0
Write:
Reset:
0
6
5
4
3
2
1
Bit 0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
0
0
0
0
0
0
0
= Unimplemented
Figure 9-5. Keyboard Interrupt Enable Register (KBIER)
KBIE5–KBIE0 — Port A Keyboard Interrupt Enable Bits
Each of these read/write bits enables the corresponding keyboard interrupt pin
on port A to latch interrupt requests. Reset clears the keyboard interrupt enable
register.
1 = KBIx pin enabled as keyboard interrupt pin
0 = KBIx pin not enabled as keyboard interrupt pin
NOTE:
AWUIE bit is not used in conjunction with the keyboard interrupt feature. To see a
description of this bit, see Section 4. Auto Wakeup Module (AWU).
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Keyboard Interrupt Module (KBI)
89
Keyboard Interrupt Module (KBI)
Data Sheet
90
MC68HC908QY/QT Family — Rev. 3
Keyboard Interrupt Module (KBI)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 10. Low-Voltage Inhibit (LVI)
10.1 Introduction
This section describes the low-voltage inhibit (LVI) module, which monitors the
voltage on the VDD pin and can force a reset when the VDD voltage falls below the
LVI trip falling voltage, VTRIPF.
10.2 Features
Features of the LVI module include:
•
Programmable LVI reset
•
Programmable power consumption
•
Selectable LVI trip voltage
•
Programmable stop mode operation
10.3 Functional Description
Figure 10-1 shows the structure of the LVI module. LVISTOP, LVIPWRD,
LVI5OR3, and LVIRSTD are user selectable options found in the configuration
register (CONFIG1). See Section 5. Configuration Register (CONFIG).
VDD
STOP INSTRUCTION
LVISTOP
FROM CONFIG
FROM CONFIG
LVIRSTD
LVIPWRD
FROM CONFIG
LOW VDD
DETECTOR
VDD > LVITRIP = 0
LVI RESET
VDD ≤ LVITRIP = 1
LVIOUT
LVI5OR3
FROM CONFIG
Figure 10-1. LVI Module Block Diagram
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Low-Voltage Inhibit (LVI)
91
Low-Voltage Inhibit (LVI)
The LVI is enabled out of reset. The LVI module contains a bandgap reference
circuit and comparator. Clearing the LVI power disable bit, LVIPWRD, enables the
LVI to monitor VDD voltage. Clearing the LVI reset disable bit, LVIRSTD, enables
the LVI module to generate a reset when VDD falls below a voltage, VTRIPF. Setting
the LVI enable in stop mode bit, LVISTOP, enables the LVI to operate in stop
mode. Setting the LVI 5-V or 3-V trip point bit, LVI5OR3, enables the trip point
voltage, VTRIPF, to be configured for 5-V operation. Clearing the LVI5OR3 bit
enables the trip point voltage, VTRIPF, to be configured for 3-V operation. The
actual trip thresholds are specified in 16.5 5-V DC Electrical Characteristics and
16.9 3-V DC Electrical Characteristics.
NOTE:
After a power-on reset, the LVI’s default mode of operation is 3 volts. If a 5-V
system is used, the user must set the LVI5OR3 bit to raise the trip point to 5-V
operation.
If the user requires 5-V mode and sets the LVI5OR3 bit after power-on reset while
the VDD supply is not above the VTRIPR for 5-V mode, the microcontroller unit
(MCU) will immediately go into reset. The next time the LVI releases the reset, the
supply will be above the VTRIPR for 5-V mode.
Once an LVI reset occurs, the MCU remains in reset until VDD rises above a
voltage, VTRIPR, which causes the MCU to exit reset. See Section 13. System
Integration Module (SIM) for the reset recovery sequence.
The output of the comparator controls the state of the LVIOUT flag in the LVI status
register (LVISR) and can be used for polling LVI operation when the LVI reset is
disabled.
10.3.1 Polled LVI Operation
In applications that can operate at VDD levels below the VTRIPF level, software can
monitor VDD by polling the LVIOUT bit. In the configuration register, the LVIPWRD
bit must be cleared to enable the LVI module, and the LVIRSTD bit must be at set
to disable LVI resets.
10.3.2 Forced Reset Operation
In applications that require VDD to remain above the VTRIPF level, enabling LVI
resets allows the LVI module to reset the MCU when VDD falls below the VTRIPF
level. In the configuration register, the LVIPWRD and LVIRSTD bits must be
cleared to enable the LVI module and to enable LVI resets.
10.3.3 Voltage Hysteresis Protection
Once the LVI has triggered (by having VDD fall below VTRIPF), the LVI will maintain
a reset condition until VDD rises above the rising trip point voltage, VTRIPR. This
prevents a condition in which the MCU is continually entering and exiting reset if
VDD is approximately equal to VTRIPF. VTRIPR is greater than VTRIPF by the
hysteresis voltage, VHYS.
Data Sheet
92
MC68HC908QY/QT Family — Rev. 3
Low-Voltage Inhibit (LVI)
MOTOROLA
Low-Voltage Inhibit (LVI)
LVI Status Register
10.3.4 LVI Trip Selection
The LVI5OR3 bit in the configuration register selects whether the LVI is configured
for 5-V or 3-V protection.
NOTE:
The microcontroller is guaranteed to operate at a minimum supply voltage. The trip
point (VTRIPF [5 V] or VTRIPF [3 V]) may be lower than this. See 16.5 5-V DC
Electrical Characteristics and 16.9 3-V DC Electrical Characteristics for the
actual trip point voltages.
10.4 LVI Status Register
The LVI status register (LVISR) indicates if the VDD voltage was detected below
the VTRIPF level while LVI resets have been disabled.
Address: $FE0C
Read:
Bit 7
6
5
4
3
2
1
Bit 0
LVIOUT
0
0
0
0
0
0
R
0
0
0
0
0
0
0
0
R
= Reserved
Write:
Reset:
= Unimplemented
Figure 10-2. LVI Status Register (LVISR)
LVIOUT — LVI Output Bit
This read-only flag becomes set when the VDD voltage falls below the VTRIPF
trip voltage and is cleared when VDD voltage rises above VTRIPR. The difference
in these threshold levels results in a hysteresis that prevents oscillation into and
out of reset (see Table 10-1). Reset clears the LVIOUT bit.
Table 10-1. LVIOUT Bit Indication
VDD
LVIOUT
VDD > VTRIPR
0
VDD < VTRIPF
1
VTRIPF < VDD < VTRIPR
Previous value
10.5 LVI Interrupts
The LVI module does not generate interrupt requests.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Low-Voltage Inhibit (LVI)
93
Low-Voltage Inhibit (LVI)
10.6 Low-Power Modes
The STOP and WAIT instructions put the MCU in low power-consumption standby
modes.
10.6.1 Wait Mode
If enabled, the LVI module remains active in wait mode. If enabled to generate
resets, the LVI module can generate a reset and bring the MCU out of wait mode.
10.6.2 Stop Mode
When the LVIPWRD bit in the configuration register is cleared and the LVISTOP
bit in the configuration register is set, the LVI module remains active in stop mode.
If enabled to generate resets, the LVI module can generate a reset and bring the
MCU out of stop mode.
Data Sheet
94
MC68HC908QY/QT Family — Rev. 3
Low-Voltage Inhibit (LVI)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 11. Oscillator Module (OSC)
11.1 Introduction
The oscillator module is used to provide a stable clock source for the
microcontroller system and bus. The oscillator module generates two output
clocks, BUSCLKX2 and BUSCLKX4. The BUSCLKX4 clock is used by the system
integration module (SIM) and the computer operating properly module (COP). The
BUSCLKX2 clock is divided by two in the SIM to be used as the bus clock for the
microcontroller. Therefore the bus frequency will be one fourth of the BUSCLKX4
frequency.
11.2 Features
The oscillator has these four clock source options available:
1. Internal oscillator: An internally generated, fixed frequency clock, trimmable
to ±5%.This is the default option out of reset.
2. External oscillator: An external clock that can be driven directly into OSC1.
3. External RC: A built-in oscillator module (RC oscillator) that requires an
external R connection only. The capacitor is internal to the chip.
4. External crystal: A built-in oscillator module (XTAL oscillator) that requires
an external crystal or ceramic-resonator.
11.3 Functional Description
The oscillator contains these major subsystems:
•
Internal oscillator circuit
•
Internal or external clock switch control
•
External clock circuit
•
External crystal circuit
•
External RC clock circuit
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Oscillator Module (OSC)
95
Oscillator Module (OSC)
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 11-1. Block Diagram Highlighting OSC Block and Pins
Data Sheet
96
MC68HC908QY/QT Family — Rev. 3
Oscillator Module (OSC)
MOTOROLA
Oscillator Module (OSC)
Functional Description
11.3.1 Internal Oscillator
The internal oscillator circuit is designed for use with no external components to
provide a clock source with tolerance less than ±25% untrimmed.An 8-bit trimming
register allows adjustment to a tolerance of less than ±5%.
The internal oscillator will generate a clock of 12.8 MHz typical (INTCLK) resulting
in a bus speed (internal clock ÷ 4) of 3.2 MHz. 3.2 MHz came from the maximum
bus speed guaranteed at 3 V which is 4 MHz.Since the internal oscillator will have
a ±25% tolerance (pre-trim), then the +25% case should not allow a frequency
higher than 4 MHz:
3.2 MHz + 25% = 4 MHz
Figure 11-3 shows how BUSCLKX4 is derived from INTCLK and, like the RC
oscillator, OSC2 can output BUSCLKX4 by setting OSC2EN in PTAPUE
register.See Section 12. Input/Output Ports (PORTS)
11.3.1.1 Internal Oscillator Trimming
The 8-bit trimming register, OSCTRIM, allows a clock period adjust of +127 and
–128 steps. Increasing OSCTRIM value increases the clock period. Trimming
allows the internal clock frequency to be set to 12.8 MHz ± 5%.
All devices are programmed with a trim value in a reserved FLASH location,
$FFC0. This value can be copied from the FLASH to the OSCTRIM register
($0038) during reset initialization.
Reset loads OSCTRIM with a default value of $80.
WARNING:
Bulk FLASH erasure will set location $FFC0 to $FF and the factory
programmed value will be lost.
11.3.1.2 Internal to External Clock Switching
When external clock source (external OSC, RC, or XTAL) is desired, the user must
perform the following steps:
1. For external crystal circuits only, OSCOPT[1:0] = 1:1: To help precharge an
external crystal oscillator, set PTA4 (OSC2) as an output and drive high for
several cycles. This may help the crystal circuit start more robustly.
2. Set CONFIG2 bits OSCOPT[1:0] according to Table 11-2. The oscillator
module control logic will then set OSC1 as an external clock input and, if the
external crystal option is selected, OSC2 will also be set as the clock output.
3. Create a software delay to wait the stabilization time needed for the selected
clock source (crystal, resonator, RC) as recommended by the component
manufacturer. A good rule of thumb for crystal oscillators is to wait 4096
cycles of the crystal frequency, i.e., for a 4-MHz crystal, wait approximately
1 msec.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Oscillator Module (OSC)
97
Oscillator Module (OSC)
4. After the manufacturer’s recommended delay has elapsed, the ECGON bit
in the OSC status register (OSCSTAT) needs to be set by the user software.
5. After ECGON set is detected, the OSC module checks for oscillator activity
by waiting two external clock rising edges.
6. The OSC module then switches to the external clock. Logic provides a glitch
free transition.
7. The OSC module first sets the ECGST bit in the OSCSTAT register and then
stops the internal oscillator.
NOTE:
Once transition to the external clock is done, the internal oscillator will only be
reactivated with reset. No post-switch clock monitor feature is implemented (clock
does not switch back to internal if external clock dies).
11.3.2 External Oscillator
The external clock option is designed for use when a clock signal is available in the
application to provide a clock source to the microcontroller. The OSC1 pin is
enabled as an input by the oscillator module. The clock signal is used directly to
create BUSCLKX4 and also divided by two to create BUSCLKX2.
In this configuration, the OSC2 pin cannot output BUSCLKX4.So the OSC2EN bit
in the port A pullup enable register will be clear to enable PTA4 I/O functions on
the pin
11.3.3 XTAL Oscillator
The XTAL oscillator circuit is designed for use with an external crystal or ceramic
resonator to provide an accurate clock source. In this configuration, the OSC2 pin
is dedicated to the external crystal circuit. The OSC2EN bit in the port A pullup
enable register has no effect when this clock mode is selected.
In its typical configuration, the XTAL oscillator is connected in a Pierce oscillator
configuration, as shown in Figure 11-2. This figure shows only the logical
representation of the internal components and may not represent actual circuitry.
The oscillator configuration uses five components:
NOTE:
•
Crystal, X1
•
Fixed capacitor, C1
•
Tuning capacitor, C2 (can also be a fixed capacitor)
•
Feedback resistor, RB
•
Series resistor, RS (optional)
The series resistor (RS) is included in the diagram to follow strict Pierce oscillator
guidelines and may not be required for all ranges of operation, especially with high
frequency crystals. Refer to the crystal manufacturer’s data for more information.
Data Sheet
98
MC68HC908QY/QT Family — Rev. 3
Oscillator Module (OSC)
MOTOROLA
Oscillator Module (OSC)
Functional Description
FROM SIM
TO SIM
BUSCLKX4
XTALCLK
TO SIM
BUSCLKX2
÷2
SIMOSCEN
MCU
OSC1
OSC2
RS(1)
RB
X1
C1
C2
Note 1.
RS can be zero (shorted) when used with higher-frequency crystals. Refer to manufacturer’s
data. See Section 16. Electrical Specifications for component value recommendations.
Figure 11-2. XTAL Oscillator External Connections
11.3.4 RC Oscillator
The RC oscillator circuit is designed for use with external R to provide a clock
source with tolerance less than 25%.
In its typical configuration, the RC oscillator requires two external components, one
R and one C. In the MC68HC908QY4, the capacitor is internal to the chip. The R
value should have a tolerance of 1% or less, to obtain a clock source with less than
25% tolerance. The oscillator configuration uses one component, REXT.
In this configuration, the OSC2 pin can be left in the reset state as PTA4. Or, the
OSC2EN bit in the port A pullup enable register can be set to enable the OSC2
output function on the pin. Enabling the OSC2 output slightly increases the external
RC oscillator frequency, fRCCLK.
See Figure 11-3
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Oscillator Module (OSC)
99
Oscillator Module (OSC)
OSCRCOPT
TO SIM
FROM SIM
INTCLK
TO SIM
0
BUSCLKX4
BUSCLKX2
1
SIMOSCEN
EXTERNAL RC
EN
OSCILLATOR
RCCLK
÷2
1
PTA4
I/O
0
PTA4
OSC2EN
MCU
OSC1
PTA4/BUSCLKX4 (OSC2)
VDD
REXT
See Section 16. Electrical Specifications for component value requirements.
Figure 11-3. RC Oscillator External Connections
11.4 Oscillator Module Signals
The following paragraphs describe the signals that are inputs to and outputs from
the oscillator module.
11.4.1 Crystal Amplifier Input Pin (OSC1)
The OSC1 pin is either an input to the crystal oscillator amplifier, an input to the RC
oscillator circuit, or an external clock source.
For the internal oscillator configuration, the OSC1 pin can assume other functions
according to Table 1-3. Function Priority in Shared Pins.
11.4.2 Crystal Amplifier Output Pin (OSC2/PTA4/BUSCLKX4)
For the XTAL oscillator device, the OSC2 pin is the crystal oscillator inverting
amplifier output.
For the external clock option, the OSC2 pin is dedicated to the PTA4 I/O function.
The OSC2EN bit has no effect.
For the internal oscillator or RC oscillator options, the OSC2 pin can assume other
functions according to Table 1-3. Function Priority in Shared Pins, or the output
of the oscillator clock (BUSCLKX4).
Data Sheet
100
MC68HC908QY/QT Family — Rev. 3
Oscillator Module (OSC)
MOTOROLA
Oscillator Module (OSC)
Oscillator Module Signals
Table 11-1. OSC2 Pin Function
Option
OSC2 Pin Function
XTAL oscillator
Inverting OSC1
External clock
PTA4 I/O
Internal oscillator
or
RC oscillator
Controlled by OSC2EN bit in PTAPUE register
OSC2EN = 0: PTA4 I/O
OSC2EN = 1: BUSCLKX4 output
11.4.3 Oscillator Enable Signal (SIMOSCEN)
The SIMOSCEN signal comes from the system integration module (SIM) and
enables/disables either the XTAL oscillator circuit, the RC oscillator, or the internal
oscillator.
11.4.4 XTAL Oscillator Clock (XTALCLK)
XTALCLK is the XTAL oscillator output signal. It runs at the full speed of the crystal
(fXCLK) and comes directly from the crystal oscillator circuit. Figure 11-2 shows
only the logical relation of XTALCLK to OSC1 and OSC2 and may not represent
the actual circuitry. The duty cycle of XTALCLK is unknown and may depend on
the crystal and other external factors. Also, the frequency and amplitude of
XTALCLK can be unstable at start up.
11.4.5 RC Oscillator Clock (RCCLK)
RCCLK is the RC oscillator output signal. Its frequency is directly proportional to
the time constant of external R and internal C. Figure 11-3 shows only the logical
relation of RCCLK to OSC1 and may not represent the actual circuitry.
11.4.6 Internal Oscillator Clock (INTCLK)
INTCLK is the internal oscillator output signal. Its nominal frequency is fixed to
12.8 MHz, but it can be also trimmed using the oscillator trimming feature of the
OSCTRIM register (see 11.3.1.1 Internal Oscillator Trimming).
11.4.7 Oscillator Out 2 (BUSCLKX4)
BUSCLKX4 is the same as the input clock (XTALCLK, RCCLK, or INTCLK). This
signal is driven to the SIM module and is used to determine the COP cycles.
11.4.8 Oscillator Out (BUSCLKX2)
The frequency of this signal is equal to half of the BUSCLKX4, this signal is driven
to the SIM for generation of the bus clocks used by the CPU and other modules on
the MCU. BUSCLKX2 will be divided again in the SIM and results in the internal
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Oscillator Module (OSC)
101
Oscillator Module (OSC)
bus frequency being one fourth of either the XTALCLK, RCCLK, or INTCLK
frequency.
11.5 Low Power Modes
The WAIT and STOP instructions put the MCU in low-power consumption standby
modes.
11.5.1 Wait Mode
The WAIT instruction has no effect on the oscillator logic. BUSCLKX2 and
BUSCLKX4 continue to drive to the SIM module.
11.5.2 Stop Mode
The STOP instruction disables either the XTALCLK, the RCCLK, or INTCLK
output, hence BUSCLKX2 and BUSCLKX4.
11.6 Oscillator During Break Mode
The oscillator continues to drive BUSCLKX2 and BUSCLKX4 when the device
enters the break state.
11.7 CONFIG2 Options
Two CONFIG2 register options affect the operation of the oscillator module:
OSCOPT1 and OSCOPT0. All CONFIG2 register bits will have a default
configuration. Refer to Section 5. Configuration Register (CONFIG) for more
information on how the CONFIG2 register is used.
Table 11-2 shows how the OSCOPT bits are used to select the oscillator clock
source.
Table 11-2. Oscillator Modes
OSCOPT1
OSCOPT0
Oscillator Modes
0
0
Internal oscillator
0
1
External oscillator
1
0
External RC
1
1
External crystal
Data Sheet
102
MC68HC908QY/QT Family — Rev. 3
Oscillator Module (OSC)
MOTOROLA
Oscillator Module (OSC)
Input/Output (I/O) Registers
11.8 Input/Output (I/O) Registers
The oscillator module contains these two registers:
1. Oscillator status register (OSCSTAT)
2. Oscillator trim register (OSCTRIM)
11.8.1 Oscillator Status Register
The oscillator status register (OSCSTAT) contains the bits for switching from
internal to external clock sources.
Address: $0036
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
R
R
R
R
R
R
ECGON
0
0
0
0
0
0
0
R
= Reserved
Bit 0
ECGST
0
= Unimplemented
Figure 11-4. Oscillator Status Register (OSCSTAT)
ECGON — External Clock Generator On Bit
This read/write bit enables external clock generator, so that the switching
process can be initiated. This bit is forced low during reset. This bit is ignored in
monitor mode with the internal oscillator bypassed, PTM or CTM mode.
1 = External clock generator enabled
0 = External clock generator disabled
ECGST — External Clock Status Bit
This read-only bit indicates whether or not an external clock source is engaged
to drive the system clock.
1 = An external clock source engaged
0 = An external clock source disengaged
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Oscillator Module (OSC)
103
Oscillator Module (OSC)
11.8.2 Oscillator Trim Register (OSCTRIM)
Address: $0038
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
TRIM7
TRIM6
TRIM5
TRIM4
TRIM3
TRIM2
TRIM1
TRIM0
1
0
0
0
0
0
0
0
Figure 11-5. Oscillator Trim Register (OSCTRIM)
TRIM7–TRIM0 — Internal Oscillator Trim Factor Bits
These read/write bits change the size of the internal capacitor used by the
internal oscillator. By measuring the period of the internal clock and adjusting
this factor accordingly, the frequency of the internal clock can be fine tuned.
Increasing (decreasing) this factor by one increases (decreases) the period by
approximately 0.2% of the untrimmed period (the period for TRIM = $80). The
trimmed frequency is guaranteed not to vary by more than ±5% over the full
specified range of temperature and voltage. The reset value is $80, which sets
the frequency to 12.8 MHz (3.2 MHz bus speed) ±25%.
Data Sheet
104
MC68HC908QY/QT Family — Rev. 3
Oscillator Module (OSC)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 12. Input/Output Ports (PORTS)
12.1 Introduction
The MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4 have five
bidirectional input-output (I/O) pins and one input only pin. The MC68HC908QY1,
MC68HC908QY2, and MC68HC908QY4 have thirteen bidirectional pins and one
input only pin. All I/O pins are programmable as inputs or outputs.
NOTE:
Connect any unused I/O pins to an appropriate logic level, either VDD or VSS.
Although the I/O ports do not require termination for proper operation, termination
reduces excess current consumption and the possibility of electrostatic damage.
Figure 12-1 provides a summary of the I/O registers.
Addr.
Register Name
Port A Data Register
(PTA)
See page 106.
$0000
Port B Data Register
(PTB)
See page 109.
$0001
$0004
$0005
$000B
$000C
Data Direction Register A
(DDRA)
See page 107.
Data Direction Register B
(DDRB)
See page 109.
Port A Input Pullup Enable
Register (PTAPUE)
See page 108.
Port B Input Pullup Enable
Register (PTBPUE)
See page 111.
Bit 7
Read:
Write:
6
AWUL
R
5
4
3
PTA5
PTA4
PTA3
Reset:
Read:
Write:
Write:
Reset:
Read:
Write:
Reset:
Read:
Write:
Reset:
Read:
Write:
Reset:
PTA2
1
Bit 0
PTA1
PTA0
PTB1
PTB0
DDRA1
DDRA0
Unaffected by reset
PTB7
PTB6
PTB5
Reset:
Read:
2
PTB4
PTB3
PTB2
Unaffected by reset
0
R
R
DDRA5
DDRA4
DDRA3
0
0
0
0
0
0
0
0
DDRB7
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
0
PTAPUE5
PTAPUE4
PTAPUE3
PTAPUE2
PTAPUE1
PTAPUE0
OSC2EN
0
0
0
0
0
0
0
0
PTBPUE7
PTBPUE6
PTBPUE5
PTBPUE4
PTBPUE3
PTBPUE2
PTBPUE1
PTBPUE0
0
0
0
0
0
0
0
0
R
= Reserved
= Unimplemented
Figure 12-1. I/O Port Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Input/Output Ports (PORTS)
105
Input/Output Ports (PORTS)
12.2 Port A
Port A is a 6-bit special function port that shares all six of its pins with the keyboard
interrupt (KBI) module (see Section 9. Keyboard Interrupt Module (KBI)). Each
port A pin also has a software configurable pullup device if the corresponding port
pin is configured as an input port.
NOTE:
PTA2 is input only.
When the IRQ function is enabled in the configuration register 2 (CONFIG2), bit 2
of the port A data register (PTA) will always read a 0. In this case, the BIH and BIL
instructions can be used to read the logic level on the PTA2 pin. When the IRQ
function is disabled, these instructions will behave as if the PTA2 pin is a logic 1.
However, reading bit 2 of PTA will read the actual logic level on the pin.
12.2.1 Port A Data Register
The port A data register (PTA) contains a data latch for each of the six port A pins.
Address: $0000
Bit 7
Read:
Write:
R
6
AWUL
5
4
3
PTA5
PTA4
PTA3
Reset:
2
PTA2
1
Bit 0
PTA1
PTA0
KBI1
KBI0
Unaffected by reset
KBI5
Additional Functions:
R
KBI4
= Reserved
KBI3
KBI2
= Unimplemented
Figure 12-2. Port A Data Register (PTA)
PTA[5:0] — Port A Data Bits
These read/write bits are software programmable. Data direction of each port A
pin is under the control of the corresponding bit in data direction register A.
Reset has no effect on port A data.
AWUL — Auto Wakeup Latch Data Bit
This is a read-only bit which has the value of the auto wakeup interrupt request
latch. The wakeup request signal is generated internally (see Section 4. Auto
Wakeup Module (AWU)). There is no PTA6 port nor any of the associated bits
such as PTA6 data register, pullup enable or direction.
KBI[5:0] — Port A Keyboard Interrupts
The keyboard interrupt enable bits, KBIE5–KBIE0, in the keyboard interrupt
control enable register (KBIER) enable the port A pins as external interrupt pins
(see Section 9. Keyboard Interrupt Module (KBI)).
Data Sheet
106
MC68HC908QY/QT Family — Rev. 3
Input/Output Ports (PORTS)
MOTOROLA
Input/Output Ports (PORTS)
Port A
12.2.2 Data Direction Register A
Data direction register A (DDRA) determines whether each port A pin is an input or
an output. Writing a 1 to a DDRA bit enables the output buffer for the corresponding
port A pin; a 0 disables the output buffer.
Address: $0004
Read:
Write:
Reset:
Bit 7
6
5
4
3
R
R
DDRA5
DDRA4
DDRA3
0
0
0
0
R
= Reserved
2
0
0
1
Bit 0
DDRA1
DDRA0
0
0
0
= Unimplemented
Figure 12-3. Data Direction Register A (DDRA)
DDRA[5:0] — Data Direction Register A Bits
These read/write bits control port A data direction. Reset clears DDRA[5:0],
configuring all port A pins as inputs.
1 = Corresponding port A pin configured as output
0 = Corresponding port A pin configured as input
NOTE:
Avoid glitches on port A pins by writing to the port A data register before changing
data direction register A bits from 0 to 1.
Figure 12-4 shows the port A I/O logic.
READ DDRA ($0004)
PTAPUEx
INTERNAL DATA BUS
WRITE DDRA ($0004)
RESET
DDRAx
30 k
WRITE PTA ($0000)
PTAx
PTAx
READ PTA ($0000)
TO KEYBOARD INTERRUPT CIRCUIT
Figure 12-4. Port A I/O Circuit
NOTE:
Figure 12-4 does not apply to PTA2
When DDRAx is a 1, reading address $0000 reads the PTAx data latch. When
DDRAx is a 0, reading address $0000 reads the voltage level on the pin. The data
latch can always be written, regardless of the state of its data direction bit.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Input/Output Ports (PORTS)
107
Input/Output Ports (PORTS)
12.2.3 Port A Input Pullup Enable Register
The port A input pullup enable register (PTAPUE) contains a software configurable
pullup device for each if the six port A pins. Each bit is individually configurable and
requires the corresponding data direction register, DDRAx, to be configured as
input. Each pullup device is automatically and dynamically disabled when its
corresponding DDRAx bit is configured as output.
Address: $000B
Bit 7
Read:
Write:
Reset:
6
OSC2EN
0
0
5
4
3
2
1
Bit 0
PTAPUE5
PTAPUE4
PTAPUE3
PTAPUE2
PTAPUE1
PTAPUE0
0
0
0
0
0
0
= Unimplemented
Figure 12-5. Port A Input Pullup Enable Register (PTAPUE)
OSC2EN — Enable PTA4 on OSC2 Pin
This read/write bit configures the OSC2 pin function when internal oscillator or
RC oscillator option is selected. This bit has no effect for the XTAL or external
oscillator options.
1 = OSC2 pin outputs the internal or RC oscillator clock (BUSCLKX4)
0 = OSC2 pin configured for PTA4 I/O, having all the interrupt and pullup
functions
PTAPUE[5:0] — Port A Input Pullup Enable Bits
These read/write bits are software programmable to enable pullup devices on
port A pins.
1 = Corresponding port A pin configured to have internal pull if its DDRA bit
is set to 0
0 = Pullup device is disconnected on the corresponding port A pin regardless
of the state of its DDRA bit
Table 12-1 summarizes the operation of the port A pins.
Table 12-1. Port A Pin Functions
PTAPUE
Bit
DDRA
Bit
PTA
Bit
I/O Pin
Mode
Accesses to DDRA
Accesses to PTA
Read/Write
Read
Write
1
0
X(1)
Input, VDD(2)
DDRA5–DDRA0
Pin
PTA5–PTA0(3)
0
0
X
Input, Hi-Z(4)
DDRA5–DDRA0
Pin
PTA5–PTA0(3)
X
1
X
Output
DDRA5–DDRA0
PTA5–PTA0
PTA5–PTA0(5)
1. X = don’t care
2. I/O pin pulled to VDD by internal pullup.
3. Writing affects data register, but does not affect input.
4. Hi-Z = high impedance
5. Output does not apply to PTA2
Data Sheet
108
MC68HC908QY/QT Family — Rev. 3
Input/Output Ports (PORTS)
MOTOROLA
Input/Output Ports (PORTS)
Port B
12.3 Port B
Port B is an 8-bit general purpose I/O port. Port B is only available on the
MC68HC908QY1, MC68HC908QY2, and MC68HC908QY4.
12.3.1 Port B Data Register
The port B data register (PTB) contains a data latch for each of the eight port B
pins.
Address: $0001
Read:
Write:
Bit 7
6
5
4
3
2
1
Bit 0
PTB7
PTB6
PTB5
PTB4
PTB3
PTB2
PTB1
PTB0
Reset:
Unaffected by reset
Figure 12-6. Port B Data Register (PTB)
PTB[7:0] — Port B Data Bits
These read/write bits are software programmable. Data direction of each port B
pin is under the control of the corresponding bit in data direction register B.
Reset has no effect on port B data.
12.3.2 Data Direction Register B
Data direction register B (DDRB) determines whether each port B pin is an input or
an output. Writing a 1 to a DDRB bit enables the output buffer for the corresponding
port B pin; a 0 disables the output buffer.
Address: $0005
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
DDRB7
DDRB6
DDRB5
DDRB4
DDRB3
DDRB2
DDRB1
DDRB0
0
0
0
0
0
0
0
0
Figure 12-7. Data Direction Register B (DDRB)
DDRB[7:0] — Data Direction Register B Bits
These read/write bits control port B data direction. Reset clears DDRB[7:0],
configuring all port B pins as inputs.
1 = Corresponding port B pin configured as output
0 = Corresponding port B pin configured as input
NOTE:
Avoid glitches on port B pins by writing to the port B data register before changing
data direction register B bits from 0 to 1. Figure 12-8 shows the port B I/O logic.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Input/Output Ports (PORTS)
109
Input/Output Ports (PORTS)
READ DDRB ($0005)
PTBPUEx
INTERNAL DATA BUS
WRITE DDRB ($0005)
RESET
DDRBx
30 k
WRITE PTB ($0001)
PTBx
PTBx
READ PTB ($0001)
Figure 12-8. Port B I/O Circuit
When DDRBx is a 1, reading address $0001 reads the PTBx data latch. When
DDRBx is a 0, reading address $0001 reads the voltage level on the pin. The data
latch can always be written, regardless of the state of its data direction bit. Table
12-2 summarizes the operation of the port B pins.
Table 12-2. Port B Pin Functions
DDRB
Bit
PTB
Bit
I/O Pin
Mode
Accesses to DDRB
Accesses to PTB
Read/Write
Read
Write
0
X(1)
Input, Hi-Z(2)
DDRB7–DDRB0
Pin
PTB7–PTB0(3)
1
X
Output
DDRB7–DDRB0
Pin
PTB7–PTB0
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect the input.
Data Sheet
110
MC68HC908QY/QT Family — Rev. 3
Input/Output Ports (PORTS)
MOTOROLA
Input/Output Ports (PORTS)
Port B
12.3.3 Port B Input Pullup Enable Register
The port B input pullup enable register (PTBPUE) contains a software configurable
pullup device for each of the eight port B pins. Each bit is individually configurable
and requires the corresponding data direction register, DDRBx, be configured as
input. Each pullup device is automatically and dynamically disabled when its
corresponding DDRBx bit is configured as output.
Address: $000C
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
PTBPUE7
PTBPUE6
PTBPUE5
PTBPUE4
PTBPUE3
PTBPUE2
PTBPUE2
PTBPUE0
0
0
0
0
0
0
0
0
Figure 12-9. Port B Input Pullup Enable Register (PTBPUE)
PTBPUE[7:0] — Port B Input Pullup Enable Bits
These read/write bits are software programmable to enable pullup devices on
port B pins
1 = Corresponding port B pin configured to have internal pull if its DDRB bit
is set to 0
0 = Pullup device is disconnected on the corresponding port B pin regardless
of the state of its DDRB bit.
Table 12-3 summarizes the operation of the port B pins.
Table 12-3. Port B Pin Functions
PTBPUE
Bit
DDRB
Bit
PTB
Bit
I/O Pin
Mode
Accesses to DDRB
Read/Write
Read
Write
1
0
X(1)
Input, VDD(2)
DDRB7–DDRB0
Pin
PTB7–PTB0(3)
0
0
X
Input, Hi-Z(4)
DDRB7–DDRB0
Pin
PTB7–PTB0(3)
X
1
X
Output
DDRB7–DDRB0
PTB7–PTB0
PTB7–PTB0
1.
2.
3.
4.
Accesses to PTB
X = don’t care
I/O pin pulled to VDD by internal pullup.
Writing affects data register, but does not affect input.
Hi-Z = high impedance
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Input/Output Ports (PORTS)
111
Input/Output Ports (PORTS)
Data Sheet
112
MC68HC908QY/QT Family — Rev. 3
Input/Output Ports (PORTS)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 13. System Integration Module (SIM)
13.1 Introduction
This section describes the system integration module (SIM), which supports up to
24 external and/or internal interrupts. Together with the central processor unit
(CPU), the SIM controls all microcontroller unit (MCU) activities. A block diagram
of the SIM is shown in Figure 13-1. Figure 13-2 is a summary of the SIM I/O
registers. The SIM is a system state controller that coordinates CPU and exception
timing.
The SIM is responsible for:
•
Bus clock generation and control for CPU and peripherals
– Stop/wait/reset/break entry and recovery
– Internal clock control
•
Master reset control, including power-on reset (POR) and computer
operating properly (COP) timeout
•
Interrupt control:
– Acknowledge timing
– Arbitration control timing
– Vector address generation
•
CPU enable/disable timing
Table 13-1. Signal Name Conventions
Signal Name
Description
BUSCLKX4
Buffered clock from the internal, RC or XTAL oscillator circuit.
BUSCLKX2
The BUSCLKX4 frequency divided by two. This signal is again divided by two in the SIM to
generate the internal bus clocks (bus clock = BUSCLKX4 ÷ 4).
Address bus
Internal address bus
Data bus
Internal data bus
PORRST
Signal from the power-on reset module to the SIM
IRST
Internal reset signal
R/W
Read/write signal
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
113
System Integration Module (SIM)
MODULE STOP
MODULE WAIT
CPU STOP (FROM CPU)
CPU WAIT (FROM CPU)
STOP/WAIT
CONTROL
SIMOSCEN (TO OSCILLATOR)
SIM
COUNTER
COP CLOCK
BUSCLKX4 (FROM OSCILLATOR)
BUSCLKX2 (FROM OSCILLATOR)
÷2
VDD
INTERNAL
PULL-UP
RESET
PIN LOGIC
CLOCK
CONTROL
CLOCK GENERATORS
POR CONTROL
MASTER
RESET
CONTROL
RESET PIN CONTROL
SIM RESET STATUS REGISTER
INTERNAL CLOCKS
ILLEGAL OPCODE (FROM CPU)
ILLEGAL ADDRESS (FROM ADDRESS
MAP DECODERS)
COP TIMEOUT (FROM COP MODULE)
LVI RESET (FROM LVI MODULE)
FORCED MON MODE ENTRY (FROM MENRST MODULE)
RESET
INTERRUPT CONTROL
AND PRIORITY DECODE
INTERRUPT SOURCES
CPU INTERFACE
Figure 13-1. SIM Block Diagram
Data Sheet
114
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Introduction
Addr.
Register Name
$FE00
Break Status Register
(BSR)
See page 155.
Bit 7
6
5
4
3
2
R
R
R
R
R
R
Read:
Bit 0
SBSW
Write:
Reset:
1
R
Note 1
0
0
0
0
0
0
0
0
1. Writing a 0 clears SBSW.
$FE01
SIM Reset Status
Register (SRSR)
See page 129.
$FE02
Reserved
$FE03
Break Flag Control
Register (BFCR)
See page 130.
$FE04
$FE05
$FE06
Interrupt Status
Register 1 (INT1)
See page 125.
Interrupt Status
Register 2 (INT2)
See page 125.
Interrupt Status
Register 3 (INT3)
See page 126.
Read:
POR
PIN
COP
ILOP
ILAD
MODRST
LVI
0
1
0
0
0
0
0
0
0
R
R
R
R
R
R
R
R
BCFE
R
R
R
R
R
R
R
Write:
POR:
Read:
Write:
Reset:
0
Read:
0
IF5
IF4
IF3
0
IF1
0
0
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
Read:
IF14
0
0
0
0
0
0
0
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
Read:
0
0
0
0
0
0
0
IF15
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
R
= Reserved
= Unimplemented
Figure 13-2. SIM I/O Register Summary
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
115
System Integration Module (SIM)
13.2 RST and IRQ Pins Initialization
RST and IRQ pins come out of reset as PTA3 and PTA2 respectively. RST and IRQ
functions can be activated by programing CONFIG2 accordingly. Refer to
Section 5. Configuration Register (CONFIG).
13.3 SIM Bus Clock Control and Generation
The bus clock generator provides system clock signals for the CPU and peripherals
on the MCU. The system clocks are generated from an incoming clock,
BUSCLKX2, as shown in Figure 13-3.
FROM
OSCILLATOR
BUSCLKX4
FROM
OSCILLATOR
BUSCLKX2
SIM COUNTER
÷2
BUS CLOCK
GENERATORS
SIM
Figure 13-3. SIM Clock Signals
13.3.1 Bus Timing
In user mode, the internal bus frequency is the oscillator frequency (BUSCLKX4)
divided by four.
13.3.2 Clock Start-Up from POR
When the power-on reset module generates a reset, the clocks to the CPU and
peripherals are inactive and held in an inactive phase until after the 4096
BUSCLKX4 cycle POR time out has completed. The IBUS clocks start upon
completion of the time out.
13.3.3 Clocks in Stop Mode and Wait Mode
Upon exit from stop mode by an interrupt or reset, the SIM allows BUSCLKX4 to
clock the SIM counter. The CPU and peripheral clocks do not become active until
after the stop delay time out. This time out is selectable as 4096 or 32 BUSCLKX4
cycles. See 13.7.2 Stop Mode.
In wait mode, the CPU clocks are inactive. The SIM also produces two sets of
clocks for other modules. Refer to the wait mode subsection of each module to see
if the module is active or inactive in wait mode. Some modules can be programmed
to be active in wait mode.
Data Sheet
116
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Reset and System Initialization
13.4 Reset and System Initialization
The MCU has these reset sources:
•
Power-on reset module (POR)
•
External reset pin (RST)
•
Computer operating properly module (COP)
•
Low-voltage inhibit module (LVI)
•
Illegal opcode
•
Illegal address
All of these resets produce the vector $FFFE–FFFF ($FEFE–FEFF in monitor
mode) and assert the internal reset signal (IRST). IRST causes all registers to be
returned to their default values and all modules to be returned to their reset states.
An internal reset clears the SIM counter (see 13.5 SIM Counter), but an external
reset does not. Each of the resets sets a corresponding bit in the SIM reset status
register (SRSR). See 13.8 SIM Registers.
13.4.1 External Pin Reset
The RST pin circuits include an internal pullup device. Pulling the asynchronous
RST pin low halts all processing. The PIN bit of the SIM reset status register
(SRSR) is set as long as RST is held low for at least the minimum tRL time.
Figure 13-4 shows the relative timing. The RST pin function is only available if the
RSTEN bit is set in the CONFIG1 register.
BUSCLKX2
RST
ADDRESS BUS
VECT H
PC
VECT L
Figure 13-4. External Reset Timing
13.4.2 Active Resets from Internal Sources
The RST pin is initially setup as a general-purpose input after a POR. Setting the
RSTEN bit in the CONFIG1 register enables the pin for the reset function. This
section assumes the RSTEN bit is set when describing activity on the RST pin.
NOTE:
For POR and LVI resets, the SIM cycles through 4096 BUSCLKX4 cycles during
which the SIM forces the RST pin low. The internal reset signal then follows the
sequence from the falling edge of RST shown in Figure 13-5.
The COP reset is asynchronous to the bus clock.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
117
System Integration Module (SIM)
The active reset feature allows the part to issue a reset to peripherals and other
chips within a system built around the MCU.
All internal reset sources actively pull the RST pin low for 32 BUSCLKX4 cycles to
allow resetting of external peripherals. The internal reset signal IRST continues to
be asserted for an additional 32 cycles (see Figure 13-5). An internal reset can be
caused by an illegal address, illegal opcode, COP time out, LVI, or POR (see
Figure 13-6).
IRST
RST
RST PULLED LOW BY MCU
32 CYCLES
32 CYCLES
BUSCLKX4
ADDRESS
BUS
VECTOR HIGH
Figure 13-5. Internal Reset Timing
ILLEGAL ADDRESS RST
ILLEGAL OPCODE RST
COPRST
POR
LVI
INTERNAL RESET
Figure 13-6. Sources of Internal Reset
Table 13-2. Reset Recovery Timing
Reset Recovery Type
Actual Number of Cycles
POR/LVI
4163 (4096 + 64 + 3)
All others
67 (64 + 3)
13.4.2.1 Power-On Reset
When power is first applied to the MCU, the power-on reset module (POR)
generates a pulse to indicate that power on has occurred. The SIM counter counts
out 4096 BUSCLKX4 cycles. Sixty-four BUSCLKX4 cycles later, the CPU and
memories are released from reset to allow the reset vector sequence to occur.
Data Sheet
118
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Reset and System Initialization
At power on, the following events occur:
•
A POR pulse is generated.
•
The internal reset signal is asserted.
•
The SIM enables the oscillator to drive BUSCLKX4.
•
Internal clocks to the CPU and modules are held inactive for
4096 BUSCLKX4 cycles to allow stabilization of the oscillator.
•
The POR bit of the SIM reset status register (SRSR) is set
See Figure 13-7.
OSC1
PORRST
4096
CYCLES
32
CYCLES
32
CYCLES
BUSCLKX4
BUSCLKX2
RST
ADDRESS BUS
$FFFE
$FFFF
Figure 13-7. POR Recovery
13.4.2.2 Computer Operating Properly (COP) Reset
An input to the SIM is reserved for the COP reset signal. The overflow of the COP
counter causes an internal reset and sets the COP bit in the SIM reset status
register (SRSR). The SIM actively pulls down the RST pin for all internal reset
sources.
To prevent a COP module time out, write any value to location $FFFF. Writing to
location $FFFF clears the COP counter and stages 12–5 of the SIM counter. The
SIM counter output, which occurs at least every (212 – 24) BUSCLKX4 cycles,
drives the COP counter. The COP should be serviced as soon as possible out of
reset to guarantee the maximum amount of time before the first time out.
The COP module is disabled during a break interrupt with monitor mode when
BDCOP bit is set in break auxiliary register (BRKAR).
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
119
System Integration Module (SIM)
13.4.2.3 Illegal Opcode Reset
The SIM decodes signals from the CPU to detect illegal instructions. An illegal
instruction sets the ILOP bit in the SIM reset status register (SRSR) and causes a
reset.
If the stop enable bit, STOP, in the mask option register is 0, the SIM treats the
STOP instruction as an illegal opcode and causes an illegal opcode reset. The SIM
actively pulls down the RST pin for all internal reset sources.
13.4.2.4 Illegal Address Reset
An opcode fetch from an unmapped address generates an illegal address reset.
The SIM verifies that the CPU is fetching an opcode prior to asserting the ILAD bit
in the SIM reset status register (SRSR) and resetting the MCU. A data fetch from
an unmapped address does not generate a reset. The SIM actively pulls down the
RST pin for all internal reset sources. See Figure 2-1. Memory Map for memory
ranges.
13.4.2.5 Low-Voltage Inhibit (LVI) Reset
The LVI asserts its output to the SIM when the VDD voltage falls to the LVI trip
voltage VTRIPF. The LVI bit in the SIM reset status register (SRSR) is set, and the
external reset pin (RST) is held low while the SIM counter counts out 4096
BUSCLKX4 cycles after VDD rises above VTRIPR. Sixty-four BUSCLKX4 cycles
later, the CPU and memories are released from reset to allow the reset vector
sequence to occur. The SIM actively pulls down the (RST) pin for all internal reset
sources.
13.5 SIM Counter
The SIM counter is used by the power-on reset module (POR) and in stop mode
recovery to allow the oscillator time to stabilize before enabling the internal bus
(IBUS) clocks. The SIM counter also serves as a prescaler for the computer
operating properly module (COP). The SIM counter uses 12 stages for counting,
followed by a 13th stage that triggers a reset of SIM counters and supplies the clock
for the COP module. The SIM counter is clocked by the falling edge of BUSCLKX4.
13.5.1 SIM Counter During Power-On Reset
The power-on reset module (POR) detects power applied to the MCU. At
power-on, the POR circuit asserts the signal PORRST. Once the SIM is initialized,
it enables the oscillator to drive the bus clock state machine.
Data Sheet
120
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Exception Control
13.5.2 SIM Counter During Stop Mode Recovery
The SIM counter also is used for stop mode recovery. The STOP instruction clears
the SIM counter. After an interrupt, break, or reset, the SIM senses the state of the
short stop recovery bit, SSREC, in the configuration register 1 (CONFIG1). If the
SSREC bit is a 1, then the stop recovery is reduced from the normal delay of 4096
BUSCLKX4 cycles down to 32 BUSCLKX4 cycles. This is ideal for applications
using canned oscillators that do not require long start-up times from stop mode.
External crystal applications should use the full stop recovery time, that is, with
SSREC cleared in the configuration register 1 (CONFIG1).
13.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter (see 13.7.2 Stop Mode for details.)
The SIM counter is free-running after all reset states. See 13.4.2 Active Resets
from Internal Sources for counter control and internal reset recovery sequences.
13.6 Exception Control
Normal sequential program execution can be changed in three different ways:
1. Interrupts
a. Maskable hardware CPU interrupts
b. Non-maskable software interrupt instruction (SWI)
2. Reset
3. Break interrupts
13.6.1 Interrupts
An interrupt temporarily changes the sequence of program execution to respond to
a particular event. Figure 13-8 flow charts the handling of system interrupts.
Interrupts are latched, and arbitration is performed in the SIM at the start of
interrupt processing. The arbitration result is a constant that the CPU uses to
determine which vector to fetch. Once an interrupt is latched by the SIM, no other
interrupt can take precedence, regardless of priority, until the latched interrupt is
serviced (or the I bit is cleared).
At the beginning of an interrupt, the CPU saves the CPU register contents on the
stack and sets the interrupt mask (I bit) to prevent additional interrupts. At the end
of an interrupt, the RTI instruction recovers the CPU register contents from the
stack so that normal processing can resume. Figure 13-9 shows interrupt entry
timing. Figure 13-10 shows interrupt recovery timing.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
121
System Integration Module (SIM)
FROM RESET
BREAK
INTERRUPT?
I BIT
SET?
YES
NO
YES
I BIT SET?
NO
IRQ
INTERRUPT?
YES
NO
TIMER
INTERRUPT?
YES
NO
STACK CPU REGISTERS
SET I BIT
LOAD PC WITH INTERRUPT VECTOR
(AS MANY INTERRUPTS AS EXIST ON CHIP)
FETCH NEXT
INSTRUCTION
SWI
INSTRUCTION?
YES
NO
RTI
INSTRUCTION?
YES
UNSTACK CPU REGISTERS
NO
EXECUTE INSTRUCTION
Figure 13-8. Interrupt Processing
Data Sheet
122
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Exception Control
MODULE
INTERRUPT
I BIT
DUMMY
ADDRESS BUS
DATA BUS
SP
DUMMY
SP – 1
SP – 2
PC – 1[7:0] PC – 1[15:8]
SP – 3
X
SP – 4
A
VECT H
CCR
VECT L
V DATA H
START ADDR
V DATA L
OPCODE
R/W
Figure 13-9. Interrupt Entry
MODULE
INTERRUPT
I BIT
ADDRESS BUS
SP – 4
DATA BUS
SP – 3
CCR
SP – 2
A
SP – 1
X
SP
PC
PC + 1
PC – 1[7:0] PC – 1[15:8] OPCODE
OPERAND
R/W
Figure 13-10. Interrupt Recovery
13.6.1.1 Hardware Interrupts
A hardware interrupt does not stop the current instruction. Processing of a
hardware interrupt begins after completion of the current instruction. When the
current instruction is complete, the SIM checks all pending hardware interrupts.
If interrupts are not masked (I bit clear in the condition code register), and if the
corresponding interrupt enable bit is set, the SIM proceeds with interrupt
processing; otherwise, the next instruction is fetched and executed.
If more than one interrupt is pending at the end of an instruction execution, the
highest priority interrupt is serviced first. Figure 13-11 demonstrates what happens
when two interrupts are pending. If an interrupt is pending upon exit from the
original interrupt service routine, the pending interrupt is serviced before the LDA
instruction is executed.
The LDA opcode is prefetched by both the INT1 and INT2 return-from-interrupt
(RTI) instructions. However, in the case of the INT1 RTI prefetch, this is a
redundant operation.
NOTE:
To maintain compatibility with the M6805 Family, the H register is not pushed on
the stack during interrupt entry. If the interrupt service routine modifies the H
register or uses the indexed addressing mode, software should save the H register
and then restore it prior to exiting the routine.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
123
System Integration Module (SIM)
CLI
LDA #$FF
INT1
BACKGROUND ROUTINE
PSHH
INT1 INTERRUPT SERVICE ROUTINE
PULH
RTI
INT2
PSHH
INT2 INTERRUPT SERVICE ROUTINE
PULH
RTI
Figure 13-11. Interrupt Recognition Example
13.6.1.2 SWI Instruction
The SWI instruction is a non-maskable instruction that causes an interrupt
regardless of the state of the interrupt mask (I bit) in the condition code register.
NOTE:
A software interrupt pushes PC onto the stack. A software interrupt does not push
PC – 1, as a hardware interrupt does.
13.6.2 Interrupt Status Registers
The flags in the interrupt status registers identify maskable interrupt sources.
Table 13-3 summarizes the interrupt sources and the interrupt status register flags
that they set. The interrupt status registers can be useful for debugging.
Table 13-3. Interrupt Sources
Priority
Highest
Source
Flag
Mask(1)
INT
Register
Flag
Vector
Address
—
—
—
$FFFE–$FFFF
Reset
SWI instruction
—
—
—
$FFFC–$FFFD
IRQ pin
IRQF
IMASK
IF1
$FFFA–$FFFB
Timer channel 0 interrupt
CH0F
CH0IE
IF3
$FFF6–$FFF7
Timer channel 1 interrupt
CH1F
CH1IE
IF4
$FFF4–$FFF5
Timer overflow interrupt
Lowest
TOF
TOIE
IF5
$FFF2–$FFF3
Keyboard interrupt
KEYF
IMASKK
IF14
$FFE0–$FFE1
ADC conversion complete interrupt
COCO
AIEN
IF15
$FFDE–$FFDF
1. The I bit in the condition code register is a global mask for all interrupt sources except the SWI
instruction.
Data Sheet
124
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Exception Control
13.6.2.1 Interrupt Status Register 1
Address: $FE04
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
IF5
IF4
IF3
0
IF1
0
0
Write:
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
= Reserved
Reset:
Figure 13-12. Interrupt Status Register 1 (INT1)
IF1 and IF3–IF5 — Interrupt Flags
These flags indicate the presence of interrupt requests from the sources shown
in Table 13-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 0, 1, 3, and 7 — Always read 0
13.6.2.2 Interrupt Status Register 2
Address: $FE05
Bit 7
6
5
4
3
2
1
Bit 0
Read:
IF14
0
0
0
0
0
0
0
Write:
R
R
R
R
R
R
R
R
0
0
0
0
0
0
0
0
R
= Reserved
Reset:
Figure 13-13. Interrupt Status Register 2 (INT2)
IF14 — Interrupt Flags
This flag indicates the presence of interrupt requests from the sources shown in
Table 13-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 0–6 — Always read 0
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
125
System Integration Module (SIM)
13.6.2.3 Interrupt Status Register 3
Address: $FE06
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
0
0
0
0
0
IF15
Write:
R
R
R
R
R
R
R
R
Reset:
0
0
0
0
0
0
0
0
R
= Reserved
Figure 13-14. Interrupt Status Register 3 (INT3)
IF15 — Interrupt Flags
These flags indicate the presence of interrupt requests from the sources shown
in Table 13-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 1–7 — Always read 0
13.6.3 Reset
All reset sources always have equal and highest priority and cannot be arbitrated.
13.6.4 Break Interrupts
The break module can stop normal program flow at a software programmable
break point by asserting its break interrupt output. (See Section 15. Development
Support.) The SIM puts the CPU into the break state by forcing it to the SWI vector
location. Refer to the break interrupt subsection of each module to see how each
module is affected by the break state.
13.6.5 Status Flag Protection in Break Mode
The SIM controls whether status flags contained in other modules can be cleared
during break mode. The user can select whether flags are protected from being
cleared by properly initializing the break clear flag enable bit (BCFE) in the break
flag control register (BFCR).
Protecting flags in break mode ensures that set flags will not be cleared while in
break mode. This protection allows registers to be freely read and written during
break mode without losing status flag information.
Setting the BCFE bit enables the clearing mechanisms. Once cleared in break
mode, a flag remains cleared even when break mode is exited. Status flags with a
two-step clearing mechanism — for example, a read of one register followed by the
read or write of another — are protected, even when the first step is accomplished
prior to entering break mode. Upon leaving break mode, execution of the second
step will clear the flag as normal.
Data Sheet
126
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
Low-Power Modes
13.7 Low-Power Modes
Executing the WAIT or STOP instruction puts the MCU in a low powerconsumption mode for standby situations. The SIM holds the CPU in a non-clocked
state. The operation of each of these modes is described below. Both STOP and
WAIT clear the interrupt mask (I) in the condition code register, allowing interrupts
to occur.
13.7.1 Wait Mode
In wait mode, the CPU clocks are inactive while the peripheral clocks continue to
run. Figure 13-15 shows the timing for wait mode entry.
ADDRESS BUS
WAIT ADDR
DATA BUS
WAIT ADDR + 1
PREVIOUS DATA
SAME
SAME
NEXT OPCODE
SAME
SAME
R/W
NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction.
Figure 13-15. Wait Mode Entry Timing
A module that is active during wait mode can wake up the CPU with an interrupt if
the interrupt is enabled. Stacking for the interrupt begins one cycle after the WAIT
instruction during which the interrupt occurred. In wait mode, the CPU clocks are
inactive. Refer to the wait mode subsection of each module to see if the module is
active or inactive in wait mode. Some modules can be programmed to be active in
wait mode.
Wait mode can also be exited by a reset (or break in emulation mode). A break
interrupt during wait mode sets the SIM break stop/wait bit, SBSW, in the break
status register (BSR). If the COP disable bit, COPD, in the configuration register
is 0, then the computer operating properly module (COP) is enabled and remains
active in wait mode.
Figure 13-16 and Figure 13-17 show the timing for wait recovery.
ADDRESS BUS
DATA BUS
$6E0B
$A6
$A6
$6E0C
$A6
$01
$00FF
$0B
$00FE
$00FD
$00FC
$6E
EXITSTOPWAIT
NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt OR break interrupt
Figure 13-16. Wait Recovery from Interrupt
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
127
System Integration Module (SIM)
32
CYCLES
ADDRESS BUS
DATA BUS
32
CYCLES
$6E0B
$A6
$A6
RSTVCT H
RSTVCT L
$A6
RST
BUSCLKX4
Figure 13-17. Wait Recovery from Internal Reset
13.7.2 Stop Mode
In stop mode, the SIM counter is reset and the system clocks are disabled. An
interrupt request from a module can cause an exit from stop mode. Stacking for
interrupts begins after the selected stop recovery time has elapsed. Reset or break
also causes an exit from stop mode.
The SIM disables the oscillator signals (BUSCLKX2 and BUSCLKX4) in stop
mode, stopping the CPU and peripherals. Stop recovery time is selectable using
the SSREC bit in the configuration register 1 (CONFIG1). If SSREC is set, stop
recovery is reduced from the normal delay of 4096 BUSCLKX4 cycles down to 32.
This is ideal for the internal oscillator, RC oscillator, and external oscillator options
which do not require long start-up times from stop mode.
NOTE:
External crystal applications should use the full stop recovery time by clearing the
SSREC bit.
The SIM counter is held in reset from the execution of the STOP instruction until
the beginning of stop recovery. It is then used to time the recovery period.
Figure 13-18 shows stop mode entry timing and Figure 13-19 shows the stop
mode recovery time from interrupt or break.
NOTE:
To minimize stop current, all pins configured as inputs should be driven to a logic 1
or logic 0.
CPUSTOP
ADDRESS BUS
DATA BUS
STOP ADDR
STOP ADDR + 1
PREVIOUS DATA
SAME
NEXT OPCODE
SAME
SAME
SAME
R/W
NOTE: Previous data can be operand data or the STOP opcode, depending on the last instruction.
Figure 13-18. Stop Mode Entry Timing
Data Sheet
128
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
System Integration Module (SIM)
SIM Registers
STOP RECOVERY PERIOD
BUSCLKX4
INTERRUPT
ADDRESS BUS
STOP + 2
STOP +1
STOP + 2
SP
SP – 1
SP – 2
SP – 3
Figure 13-19. Stop Mode Recovery from Interrupt
13.8 SIM Registers
The SIM has three memory mapped registers. Table 13-4 shows the mapping of
these registers.
Table 13-4. SIM Registers
Address
Register
Access Mode
$FE00
BSR
User
$FE01
SRSR
User
$FE03
BFCR
User
13.8.1 SIM Reset Status Register
This register contains seven flags that show the source of the last reset. Clear the
SIM reset status register by reading it. A power-on reset sets the POR bit.
Address: $FE01
Read:
Bit 7
6
5
4
3
2
1
Bit 0
POR
PIN
COP
ILOP
ILAD
MODRST
LVI
0
1
0
0
0
0
0
0
0
Write:
POR:
= Unimplemented
Figure 13-20. SIM Reset Status Register (SRSR)
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of SRSR
PIN — External Reset Bit
1 = Last reset caused by external reset pin (RST)
0 = POR or read of SRSR
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
System Integration Module (SIM)
129
System Integration Module (SIM)
COP — Computer Operating Properly Reset Bit
1 = Last reset caused by COP counter
0 = POR or read of SRSR
ILOP — Illegal Opcode Reset Bit
1 = Last reset caused by an illegal opcode
0 = POR or read of SRSR
ILAD — Illegal Address Reset Bit (illegal attempt to fetch an opcode from an
unimplemented address)
1 = Last reset caused by an opcode fetch from an illegal address
0 = POR or read of SRSR
MODRST — Monitor Mode Entry Module Reset bit
1 = Last reset caused by monitor mode entry when vector locations $FFFE
and $FFFF are $FF after POR while IRQ = VDD
0 = POR or read of SRSR
LVI — Low Voltage Inhibit Reset bit
1 = Last reset caused by LVI circuit
0 = POR or read of SRSR
13.8.2 Break Flag Control Register
The break control register (BFCR) contains a bit that enables software to clear
status bits while the MCU is in a break state.
Address: $FE03
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
BCFE
R
R
R
R
R
R
R
0
R
= Reserved
Figure 13-21. Break Flag Control Register (BFCR)
BCFE — Break Clear Flag Enable Bit
This read/write bit enables software to clear status bits by accessing status
registers while the MCU is in a break state. To clear status bits during the break
state, the BCFE bit must be set.
1 = Status bits clearable during break
0 = Status bits not clearable during break
Data Sheet
130
MC68HC908QY/QT Family — Rev. 3
System Integration Module (SIM)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 14. Timer Interface Module (TIM)
14.1 Introduction
This section describes the timer interface module (TIM). The TIM is a two-channel
timer that provides a timing reference with input capture, output compare, and
pulse-width-modulation functions. Figure 14-2 is a block diagram of the TIM.
14.2 Features
Features of the TIM include the following:
•
Two input capture/output compare channels
– Rising-edge, falling-edge, or any-edge input capture trigger
– Set, clear, or toggle output compare action
•
Buffered and unbuffered pulse width modulation (PWM) signal generation
•
Programmable TIM clock input
– 7-frequency internal bus clock prescaler selection
– External TIM clock input
•
Free-running or modulo up-count operation
•
Toggle any channel pin on overflow
•
TIM counter stop and reset bits
14.3 Pin Name Conventions
The TIM shares two input/output (I/O) pins with two port A I/O pins. The full names
of the TIM I/O pins are listed in Table 14-1. The generic pin name appear in the
text that follows.
Table 14-1. Pin Name Conventions
TIM Generic Pin Names:
Full TIM Pin Names:
TCH0
TCH1
TCLK
PTA0/TCH0
PTA1/TCH1
PTA2/TCLK
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
131
Timer Interface Module (TIM)
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
PTB
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 14-1. Block Diagram Highlighting TIM Block and Pins
Data Sheet
132
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Functional Description
14.4 Functional Description
Figure 14-2 shows the structure of the TIM. The central component of the TIM is
the 16-bit TIM counter that can operate as a free-running counter or a modulo
up-counter. The TIM counter provides the timing reference for the input capture
and output compare functions. The TIM counter modulo registers,
TMODH:TMODL, control the modulo value of the TIM counter. Software can read
the TIM counter value at any time without affecting the counting sequence.
The two TIM channels are programmable independently as input capture or output
compare channels.
PTA2/IRQ/KBI2/TCLK
PRESCALER SELECT
INTERNAL
BUS CLOCK
PRESCALER
TSTOP
PS2
TRST
PS1
PS0
16-BIT COUNTER
TOF
TOIE
INTERRUPT
LOGIC
16-BIT COMPARATOR
TMODH:TMODL
TOV0
CHANNEL 0
ELS0B
ELS0A
CH0MAX
16-BIT COMPARATOR
TCH0H:TCH0L
PORT
LOGIC
TCH0
CH0F
16-BIT LATCH
CH0IE
MS0A
INTERRUPT
LOGIC
MS0B
INTERNAL BUS
TOV1
CHANNEL 1
ELS1B
ELS1A
CH1MAX
PORT
LOGIC
TCH1
16-BIT COMPARATOR
TCH1H:TCH1L
CH1F
16-BIT LATCH
MS1A
CH1IE
INTERRUPT
LOGIC
Figure 14-2. TIM Block Diagram
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
133
Timer Interface Module (TIM)
Addr.
Register Name
$0020
TIM Status and Control
Register (TSC)
See page 141.
$0021
$0022
$0023
$0024
$0025
$0026
$0027
$0028
$0029
$002A
TIM Counter Register High
(TCNTH)
See page 143.
TIM Counter Register Low
(TCNTL)
See page 143.
TIM Counter Modulo Register
High (TMODH)
See page 143.
TIM Counter Modulo Register
Low (TMODL)
See page 143.
TIM Channel 0 Status and
Control Register (TSC0)
See page 144.
TIM Channel 0 Register High
(TCH0H)
See page 147.
TIM Channel 0 Register Low
(TCH0L)
See page 147.
TIM Channel 1 Status and
Control Register (TSC1)
See page 144.
TIM Channel 1 Register High
(TCH1H)
See page 147.
TIM Channel 1 Register Low
(TCH1L)
See page 147.
Bit 7
6
5
TOIE
TSTOP
4
3
0
0
2
1
Bit 0
PS2
PS1
PS0
Read:
TOF
Write:
0
Reset:
0
0
1
0
0
0
0
0
Read:
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Reset:
0
0
0
0
0
0
0
0
Read:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
1
1
1
1
1
1
1
1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset:
1
1
1
1
1
1
1
1
Read:
CH0F
Write:
0
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
Reset:
0
0
0
0
0
0
0
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 2
Bit 1
Bit 0
TRST
Write:
Write:
Reset:
Read:
Write:
Reset:
Read:
Write:
Read:
Write:
Reset:
Read:
Write:
Indeterminate after reset
Bit 7
Bit 6
Bit 5
Reset:
CH1F
Write:
0
Reset:
0
0
Bit 15
Bit 14
Write:
CH1IE
0
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
0
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 2
Bit 1
Bit 0
Reset:
Read:
Write:
Bit 3
Indeterminate after reset
Read:
Read:
Bit 4
Indeterminate after reset
Bit 7
Bit 6
Bit 5
Reset:
Bit 4
Bit 3
Indeterminate after reset
= Unimplemented
Figure 14-3. TIM I/O Register Summary
Data Sheet
134
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Functional Description
14.4.1 TIM Counter Prescaler
The TIM clock source is one of the seven prescaler outputs or the TIM clock pin,
TCLK. The prescaler generates seven clock rates from the internal bus clock. The
prescaler select bits, PS[2:0], in the TIM status and control register (TSC) select
the TIM clock source.
14.4.2 Input Capture
With the input capture function, the TIM can capture the time at which an external
event occurs. When an active edge occurs on the pin of an input capture channel,
the TIM latches the contents of the TIM counter into the TIM channel registers,
TCHxH:TCHxL. The polarity of the active edge is programmable. Input captures
can generate TIM central processor unit (CPU) interrupt requests.
14.4.3 Output Compare
With the output compare function, the TIM can generate a periodic pulse with a
programmable polarity, duration, and frequency. When the counter reaches the
value in the registers of an output compare channel, the TIM can set, clear, or
toggle the channel pin. Output compares can generate TIM CPU interrupt
requests.
14.4.3.1 Unbuffered Output Compare
Any output compare channel can generate unbuffered output compare pulses as
described in 14.4.3 Output Compare. The pulses are unbuffered because
changing the output compare value requires writing the new value over the old
value currently in the TIM channel registers.
An unsynchronized write to the TIM channel registers to change an output compare
value could cause incorrect operation for up to two counter overflow periods. For
example, writing a new value before the counter reaches the old value but after the
counter reaches the new value prevents any compare during that counter overflow
period. Also, using a TIM overflow interrupt routine to write a new, smaller output
compare value may cause the compare to be missed. The TIM may pass the new
value before it is written.
Use the following methods to synchronize unbuffered changes in the output
compare value on channel x:
• When changing to a smaller value, enable channel x output compare
interrupts and write the new value in the output compare interrupt routine.
The output compare interrupt occurs at the end of the current output
compare pulse. The interrupt routine has until the end of the counter
overflow period to write the new value.
• When changing to a larger output compare value, enable TIM overflow
interrupts and write the new value in the TIM overflow interrupt routine. The
TIM overflow interrupt occurs at the end of the current counter overflow
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
135
Timer Interface Module (TIM)
period. Writing a larger value in an output compare interrupt routine (at the
end of the current pulse) could cause two output compares to occur in the
same counter overflow period.
14.4.3.2 Buffered Output Compare
Channels 0 and 1 can be linked to form a buffered output compare channel whose
output appears on the TCH0 pin. The TIM channel registers of the linked pair
alternately control the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links
channel 0 and channel 1. The output compare value in the TIM channel 0 registers
initially controls the output on the TCH0 pin. Writing to the TIM channel 1 registers
enables the TIM channel 1 registers to synchronously control the output after the
TIM overflows. At each subsequent overflow, the TIM channel registers (0 or 1) that
control the output are the ones written to last. TSC0 controls and monitors the
buffered output compare function, and TIM channel 1 status and control register
(TSC1) is unused. While the MS0B bit is set, the channel 1 pin, TCH1, is available
as a general-purpose I/O pin.
NOTE:
In buffered output compare operation, do not write new output compare values to
the currently active channel registers. User software should track the currently
active channel to prevent writing a new value to the active channel. Writing to the
active channel registers is the same as generating unbuffered output compares.
14.4.4 Pulse Width Modulation (PWM)
By using the toggle-on-overflow feature with an output compare channel, the TIM
can generate a PWM signal. The value in the TIM counter modulo registers
determines the period of the PWM signal. The channel pin toggles when the
counter reaches the value in the TIM counter modulo registers. The time between
overflows is the period of the PWM signal
As Figure 14-4 shows, the output compare value in the TIM channel registers
determines the pulse width of the PWM signal. The time between overflow and
output compare is the pulse width. Program the TIM to clear the channel pin on
output compare if the state of the PWM pulse is logic 1 (ELSxA = 0). Program the
TIM to set the pin if the state of the PWM pulse is logic 0 (ELSxA = 1).
The value in the TIM counter modulo registers and the selected prescaler output
determines the frequency of the PWM output The frequency of an 8-bit PWM signal
is variable in 256 increments. Writing $00FF (255) to the TIM counter modulo
registers produces a PWM period of 256 times the internal bus clock period if the
prescaler select value is 000. See 14.9.1 TIM Status and Control Register.
The value in the TIM channel registers determines the pulse width of the PWM
output. The pulse width of an 8-bit PWM signal is variable in 256 increments.
Writing $0080 (128) to the TIM channel registers produces a duty cycle of 128/256
or 50%.
Data Sheet
136
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Functional Description
OVERFLOW
OVERFLOW
OVERFLOW
PERIOD
POLARITY = 1
(ELSxA = 0)
TCHx
PULSE
WIDTH
POLARITY = 0
(ELSxA = 1)
TCHx
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
Figure 14-4. PWM Period and Pulse Width
14.4.4.1 Unbuffered PWM Signal Generation
Any output compare channel can generate unbuffered PWM pulses as described
in 14.4.4 Pulse Width Modulation (PWM). The pulses are unbuffered because
changing the pulse width requires writing the new pulse width value over the old
value currently in the TIM channel registers.
An unsynchronized write to the TIM channel registers to change a pulse width
value could cause incorrect operation for up to two PWM periods. For example,
writing a new value before the counter reaches the old value but after the counter
reaches the new value prevents any compare during that PWM period. Also, using
a TIM overflow interrupt routine to write a new, smaller pulse width value may
cause the compare to be missed. The TIM may pass the new value before it is
written.
Use the following methods to synchronize unbuffered changes in the PWM pulse
width on channel x:
NOTE:
•
When changing to a shorter pulse width, enable channel x output compare
interrupts and write the new value in the output compare interrupt routine.
The output compare interrupt occurs at the end of the current pulse. The
interrupt routine has until the end of the PWM period to write the new value.
•
When changing to a longer pulse width, enable TIM overflow interrupts and
write the new value in the TIM overflow interrupt routine. The TIM overflow
interrupt occurs at the end of the current PWM period. Writing a larger value
in an output compare interrupt routine (at the end of the current pulse) could
cause two output compares to occur in the same PWM period.
In PWM signal generation, do not program the PWM channel to toggle on output
compare. Toggling on output compare prevents reliable 0% duty cycle generation
and removes the ability of the channel to self-correct in the event of software error
or noise. Toggling on output compare also can cause incorrect PWM signal
generation when changing the PWM pulse width to a new, much larger value.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
137
Timer Interface Module (TIM)
14.4.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel whose output
appears on the TCH0 pin. The TIM channel registers of the linked pair alternately
control the pulse width of the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links
channel 0 and channel 1. The TIM channel 0 registers initially control the pulse
width on the TCH0 pin. Writing to the TIM channel 1 registers enables the TIM
channel 1 registers to synchronously control the pulse width at the beginning of the
next PWM period. At each subsequent overflow, the TIM channel registers (0 or 1)
that control the pulse width are the ones written to last. TSC0 controls and monitors
the buffered PWM function, and TIM channel 1 status and control register (TSC1)
is unused. While the MS0B bit is set, the channel 1 pin, TCH1, is available as a
general-purpose I/O pin.
NOTE:
In buffered PWM signal generation, do not write new pulse width values to the
currently active channel registers. User software should track the currently active
channel to prevent writing a new value to the active channel. Writing to the active
channel registers is the same as generating unbuffered PWM signals.
14.4.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered PWM signals,
use the following initialization procedure:
1. In the TIM status and control register (TSC):
a. Stop the TIM counter by setting the TIM stop bit, TSTOP.
b. Reset the TIM counter and prescaler by setting the TIM reset bit,
TRST.
2. In the TIM counter modulo registers (TMODH:TMODL), write the value for
the required PWM period.
3. In the TIM channel x registers (TCHxH:TCHxL), write the value for the
required pulse width.
4. In TIM channel x status and control register (TSCx):
a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for
buffered output compare or PWM signals) to the mode select bits,
MSxB:MSxA. See Table 14-3.
b. Write 1 to the toggle-on-overflow bit, TOVx.
c. Write 1:0 (polarity 1 — to clear output on compare) or 1:1 (polarity 0 —
to set output on compare) to the edge/level select bits, ELSxB:ELSxA.
The output action on compare must force the output to the complement
of the pulse width level. See Table 14-3.
NOTE:
In PWM signal generation, do not program the PWM channel to toggle on output
compare. Toggling on output compare prevents reliable 0% duty cycle generation
and removes the ability of the channel to self-correct in the event of software error
Data Sheet
138
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Interrupts
or noise. Toggling on output compare can also cause incorrect PWM signal
generation when changing the PWM pulse width to a new, much larger value.
5. In the TIM status control register (TSC), clear the TIM stop bit, TSTOP.
Setting MS0B links channels 0 and 1 and configures them for buffered PWM
operation. The TIM channel 0 registers (TCH0H:TCH0L) initially control the
buffered PWM output. TIM status control register 0 (TSCR0) controls and monitors
the PWM signal from the linked channels. MS0B takes priority over MS0A.
Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIM overflows.
Subsequent output compares try to force the output to a state it is already in and
have no effect. The result is a 0% duty cycle output.
Setting the channel x maximum duty cycle bit (CHxMAX) and setting the TOVx bit
generates a 100% duty cycle output. See 14.9.4 TIM Channel Status and Control
Registers.
14.5 Interrupts
The following TIM sources can generate interrupt requests:
•
TIM overflow flag (TOF) — The TOF bit is set when the TIM counter reaches
the modulo value programmed in the TIM counter modulo registers. The TIM
overflow interrupt enable bit, TOIE, enables TIM overflow CPU interrupt
requests. TOF and TOIE are in the TIM status and control register.
•
TIM channel flags (CH1F:CH0F) — The CHxF bit is set when an input
capture or output compare occurs on channel x. Channel x TIM CPU
interrupt requests are controlled by the channel x interrupt enable bit,
CHxIE. Channel x TIM CPU interrupt requests are enabled when CHxIE =1.
CHxF and CHxIE are in the TIM channel x status and control register.
14.6 Wait Mode
The WAIT instruction puts the MCU in low power-consumption standby mode.
The TIM remains active after the execution of a WAIT instruction. In wait mode the
TIM registers are not accessible by the CPU. Any enabled CPU interrupt request
from the TIM can bring the MCU out of wait mode.
If TIM functions are not required during wait mode, reduce power consumption by
stopping the TIM before executing the WAIT instruction.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
139
Timer Interface Module (TIM)
14.7 TIM During Break Interrupts
A break interrupt stops the TIM counter.
The system integration module (SIM) controls whether status bits in other modules
can be cleared during the break state. The BCFE bit in the break flag control
register (BFCR) enables software to clear status bits during the break state. See
13.8.2 Break Flag Control Register.
To allow software to clear status bits during a break interrupt, write a 1 to the BCFE
bit. If a status bit is cleared during the break state, it remains cleared when the MCU
exits the break state.
To protect status bits during the break state, write a 0 to the BCFE bit. With BCFE
at 0 (its default state), software can read and write I/O registers during the break
state without affecting status bits. Some status bits have a two-step read/write
clearing procedure. If software does the first step on such a bit before the break,
the bit cannot change during the break state as long as BCFE is at 0. After the
break, doing the second step clears the status bit.
14.8 Input/Output Signals
Port A shares three of its pins with the TIM. Two TIM channel I/O pins are
PTA0/TCH0 and PTA1/TCH1 and an alternate clock source is PTA2/TCLK.
14.8.1 TIM Clock Pin (PTA2/TCLK)
PTA2/TCLK is an external clock input that can be the clock source for the TIM
counter instead of the prescaled internal bus clock. Select the PTA2/TCLK input
by writing 1s to the three prescaler select bits, PS[2–0]. (See 14.9.1 TIM Status
and Control Register.) When the PTA2/TCLK pin is the TIM clock input, it is an
input regardless of port pin initialization.
14.8.2 TIM Channel I/O Pins (PTA0/TCH0 and PTA1/TCH1)
Each channel I/O pin is programmable independently as an input capture pin or an
output compare pin. PTA0/TCH0 can be configured as a buffered output compare
or buffered PWM pin.
Data Sheet
140
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Input/Output Registers
14.9 Input/Output Registers
The following I/O registers control and monitor operation of the TIM:
• TIM status and control register (TSC)
• TIM counter registers (TCNTH:TCNTL)
• TIM counter modulo registers (TMODH:TMODL)
• TIM channel status and control registers (TSC0 and TSC1)
• TIM channel registers (TCH0H:TCH0L and TCH1H:TCH1L)
14.9.1 TIM Status and Control Register
The TIM status and control register (TSC) does the following:
• Enables TIM overflow interrupts
• Flags TIM overflows
• Stops the TIM counter
• Resets the TIM counter
• Prescales the TIM counter clock
Address: $0020
Bit 7
Read:
TOF
Write:
0
Reset:
0
6
5
TOIE
TSTOP
0
1
4
3
0
0
TRST
0
0
2
1
Bit 0
PS2
PS1
PS0
0
0
0
= Unimplemented
Figure 14-5. TIM Status and Control Register (TSC)
TOF — TIM Overflow Flag Bit
This read/write flag is set when the TIM counter reaches the modulo value
programmed in the TIM counter modulo registers. Clear TOF by reading the TIM
status and control register when TOF is set and then writing a 0 to TOF. If
another TIM overflow occurs before the clearing sequence is complete, then
writing 0 to TOF has no effect. Therefore, a TOF interrupt request cannot be lost
due to inadvertent clearing of TOF. Reset clears the TOF bit. Writing a 1 to TOF
has no effect.
1 = TIM counter has reached modulo value
0 = TIM counter has not reached modulo value
TOIE — TIM Overflow Interrupt Enable Bit
This read/write bit enables TIM overflow interrupts when the TOF bit becomes
set. Reset clears the TOIE bit.
1 = TIM overflow interrupts enabled
0 = TIM overflow interrupts disabled
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
141
Timer Interface Module (TIM)
TSTOP — TIM Stop Bit
This read/write bit stops the TIM counter. Counting resumes when TSTOP is
cleared. Reset sets the TSTOP bit, stopping the TIM counter until software
clears the TSTOP bit.
1 = TIM counter stopped
0 = TIM counter active
NOTE:
Do not set the TSTOP bit before entering wait mode if the TIM is required to exit
wait mode.
TRST — TIM Reset Bit
Setting this write-only bit resets the TIM counter and the TIM prescaler. Setting
TRST has no effect on any other registers. Counting resumes from $0000.
TRST is cleared automatically after the TIM counter is reset and always reads
as a 0. Reset clears the TRST bit.
1 = Prescaler and TIM counter cleared
0 = No effect
NOTE:
Setting the TSTOP and TRST bits simultaneously stops the TIM counter at a value
of $0000.
PS[2:0] — Prescaler Select Bits
These read/write bits select either the PTA2/TCLK pin or one of the seven
prescaler outputs as the input to the TIM counter as Table 14-2 shows. Reset
clears the PS[2:0] bits.
Table 14-2. Prescaler Selection
PS2
PS1
PS0
TIM Clock Source
0
0
0
Internal bus clock ÷ 1
0
0
1
Internal bus clock ÷ 2
0
1
0
Internal bus clock ÷ 4
0
1
1
Internal bus clock ÷ 8
1
0
0
Internal bus clock ÷ 16
1
0
1
Internal bus clock ÷ 32
1
1
0
Internal bus clock ÷ 64
1
1
1
PTA2/TCLK
Data Sheet
142
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Input/Output Registers
14.9.2 TIM Counter Registers
The two read-only TIM counter registers contain the high and low bytes of the value
in the TIM counter. Reading the high byte (TCNTH) latches the contents of the low
byte (TCNTL) into a buffer. Subsequent reads of TCNTH do not affect the latched
TCNTL value until TCNTL is read. Reset clears the TIM counter registers. Setting
the TIM reset bit (TRST) also clears the TIM counter registers.
NOTE:
If you read TCNTH during a break interrupt, be sure to unlatch TCNTL by reading
TCNTL before exiting the break interrupt. Otherwise, TCNTL retains the value
latched during the break.
Address: $0021
Read:
TCNTH
Bit 7
6
5
4
3
2
1
Bit 0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
0
0
0
0
0
0
0
0
Write:
Reset:
Address: $0022
Read:
TCNTL
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
Write:
Reset:
0
= Unimplemented
Figure 14-6. TIM Counter Registers (TCNTH:TCNTL)
14.9.3 TIM Counter Modulo Registers
The read/write TIM modulo registers contain the modulo value for the TIM counter.
When the TIM counter reaches the modulo value, the overflow flag (TOF) becomes
set, and the TIM counter resumes counting from $0000 at the next timer clock.
Writing to the high byte (TMODH) inhibits the TOF bit and overflow interrupts until
the low byte (TMODL) is written. Reset sets the TIM counter modulo registers.
Address: $0023
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
1
1
1
1
1
1
1
1
Address: $0024
Read:
Write:
Reset:
TMODH
TMODL
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
1
1
1
1
1
1
1
Figure 14-7. TIM Counter Modulo Registers (TMODH:TMODL)
NOTE:
Reset the TIM counter before writing to the TIM counter modulo registers.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
143
Timer Interface Module (TIM)
14.9.4 TIM Channel Status and Control Registers
Each of the TIM channel status and control registers does the following:
•
Flags input captures and output compares
•
Enables input capture and output compare interrupts
•
Selects input capture, output compare, or PWM operation
•
Selects high, low, or toggling output on output compare
•
Selects rising edge, falling edge, or any edge as the active input capture
trigger
•
Selects output toggling on TIM overflow
•
Selects 0% and 100% PWM duty cycle
•
Selects buffered or unbuffered output compare/PWM operation
Address: $0025
Bit 7
TSC0
6
5
4
3
2
1
Bit 0
CH0IE
MS0B
MS0A
ELS0B
ELS0A
TOV0
CH0MAX
0
0
0
0
0
0
0
0
Address: $0028
TSC1
5
4
3
2
1
Bit 0
MS1A
ELS1B
ELS1A
TOV1
CH1MAX
0
0
0
0
0
Read:
CH0F
Write:
0
Reset:
Bit 7
Read:
CH1F
Write:
0
Reset:
0
6
CH1IE
0
0
0
= Unimplemented
Figure 14-8. TIM Channel Status and Control
Registers (TSC0:TSC1)
CHxF — Channel x Flag Bit
When channel x is an input capture channel, this read/write bit is set when an
active edge occurs on the channel x pin. When channel x is an output compare
channel, CHxF is set when the value in the TIM counter registers matches the
value in the TIM channel x registers.
Clear CHxF by reading the TIM channel x status and control register with CHxF
set and then writing a 0 to CHxF. If another interrupt request occurs before the
clearing sequence is complete, then writing a 0 to CHxF has no effect.
Therefore, an interrupt request cannot be lost due to inadvertent clearing of
CHxF.
Reset clears the CHxF bit. Writing a 1 to CHxF has no effect.
1 = Input capture or output compare on channel x
0 = No input capture or output compare on channel x
Data Sheet
144
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Input/Output Registers
CHxIE — Channel x Interrupt Enable Bit
This read/write bit enables TIM CPU interrupt service requests on channel x.
Reset clears the CHxIE bit.
1 = Channel x CPU interrupt requests enabled
0 = Channel x CPU interrupt requests disabled
MSxB — Mode Select Bit B
This read/write bit selects buffered output compare/PWM operation. MSxB
exists only in the TIM channel 0 status and control register.
Setting MS0B disables the channel 1 status and control register and reverts
TCH1 to general-purpose I/O.
Reset clears the MSxB bit.
1 = Buffered output compare/PWM operation enabled
0 = Buffered output compare/PWM operation disabled
MSxA — Mode Select Bit A
When ELSxB:A ≠ 00, this read/write bit selects either input capture operation or
unbuffered output compare/PWM operation. See Table 14-3.
1 = Unbuffered output compare/PWM operation
0 = Input capture operation
When ELSxB:A = 00, this read/write bit selects the initial output level of the
TCHx pin (see Table 14-3). Reset clears the MSxA bit.
1 = Initial output level low
0 = Initial output level high
NOTE:
Before changing a channel function by writing to the MSxB or MSxA bit, set the
TSTOP and TRST bits in the TIM status and control register (TSC).
Table 14-3. Mode, Edge, and Level Selection
MSxB
MSxA
ELSxB
ELSxA
X
0
0
0
Mode
Output preset
Pin under port control;
initial output level high
X
1
0
0
Pin under port control;
initial output level low
0
0
0
1
Capture on rising edge only
0
0
1
0
0
0
1
1
0
1
0
0
Software compare only
0
1
0
1
Toggle output on compare
0
1
1
0
0
1
1
1
1
X
0
1
1
X
1
0
1
X
1
1
Input capture
Capture on falling edge only
Capture on rising
or falling edge
Output compare
or PWM
Clear output on compare
Set output on compare
Buffered
output
compare or
buffered PWM
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Configuration
Toggle output on compare
Clear output on compare
Set output on compare
Data Sheet
Timer Interface Module (TIM)
145
Timer Interface Module (TIM)
ELSxB and ELSxA — Edge/Level Select Bits
When channel x is an input capture channel, these read/write bits control the
active edge-sensing logic on channel x.
When channel x is an output compare channel, ELSxB and ELSxA control the
channel x output behavior when an output compare occurs.
When ELSxB and ELSxA are both clear, channel x is not connected to an I/O
port, and pin TCHx is available as a general-purpose I/O pin. Table 14-3 shows
how ELSxB and ELSxA work. Reset clears the ELSxB and ELSxA bits.
NOTE:
After initially enabling a TIM channel register for input capture operation and
selecting the edge sensitivity, clear CHxF to ignore any erroneous edge detection
flags.
TOVx — Toggle-On-Overflow Bit
When channel x is an output compare channel, this read/write bit controls the
behavior of the channel x output when the TIM counter overflows. When
channel x is an input capture channel, TOVx has no effect Reset clears the
TOVx bit.
1 = Channel x pin toggles on TIM counter overflow.
0 = Channel x pin does not toggle on TIM counter overflow.
NOTE:
When TOVx is set, a TIM counter overflow takes precedence over a channel x
output compare if both occur at the same time.
CHxMAX — Channel x Maximum Duty Cycle Bit
When the TOVx bit is at a 1, setting the CHxMAX bit forces the duty cycle of
buffered and unbuffered PWM signals to 100%. As Figure 14-9 shows, the
CHxMAX bit takes effect in the cycle after it is set or cleared. The output stays
at the 100% duty cycle level until the cycle after CHxMAX is cleared.
OVERFLOW
OVERFLOW
OVERFLOW
OVERFLOW
OVERFLOW
PERIOD
TCHx
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
CHxMAX
Figure 14-9. CHxMAX Latency
Data Sheet
146
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Timer Interface Module (TIM)
Input/Output Registers
14.9.5 TIM Channel Registers
These read/write registers contain the captured TIM counter value of the input
capture function or the output compare value of the output compare function. The
state of the TIM channel registers after reset is unknown.
In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the TIM
channel x registers (TCHxH) inhibits input captures until the low byte (TCHxL) is
read.
In output compare mode (MSxB:MSxA ≠ 0:0), writing to the high byte of the TIM
channel x registers (TCHxH) inhibits output compares until the low byte (TCHxL) is
written.
Address: $0026
Read:
Write:
TCH0H
Bit 7
6
5
4
3
2
1
Bit 0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Reset:
Indeterminate after reset
Address: $0027
Read:
Write:
TCH0L
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset:
Indeterminate after reset
Address: $0029
Read:
Write:
TCH1H
Bit 7
6
5
4
3
2
1
Bit 0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Reset:
Indeterminate after reset
Address: $02A
Read:
Write:
Reset:
TCH1L
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Indeterminate after reset
Figure 14-10. TIM Channel Registers (TCH0H/L:TCH1H/L)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Timer Interface Module (TIM)
147
Timer Interface Module (TIM)
Data Sheet
148
MC68HC908QY/QT Family — Rev. 3
Timer Interface Module (TIM)
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 15. Development Support
15.1 Introduction
This section describes the break module, the monitor read-only memory (MON),
and the monitor mode entry methods.
15.2 Break Module (BRK)
The break module can generate a break interrupt that stops normal program flow
at a defined address to enter a background program.
Features include:
•
Accessible input/output (I/O) registers during the break Interrupt
•
Central processor unit (CPU) generated break interrupts
•
Software-generated break interrupts
•
Computer operating properly (COP) disabling during break interrupts
15.2.1 Functional Description
When the internal address bus matches the value written in the break address
registers, the break module issues a breakpoint signal (BKPT) to the system
integration module (SIM). The SIM then causes the CPU to load the instruction
register with a software interrupt instruction (SWI). The program counter vectors to
$FFFC and $FFFD ($FEFC and $FEFD in monitor mode).
The following events can cause a break interrupt to occur:
•
A CPU generated address (the address in the program counter) matches
the contents of the break address registers.
•
Software writes a 1 to the BRKA bit in the break status and control register.
When a CPU generated address matches the contents of the break address
registers, the break interrupt is generated. A return-from-interrupt instruction (RTI)
in the break routine ends the break interrupt and returns the microcontroller unit
(MCU) to normal operation.
Figure 15-2 shows the structure of the break module.
Figure 15-3 provides a summary of the I/O registers.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Development Support
149
Development Support
PTA0/AD0/TCH0/KBI0
CLOCK
GENERATOR
(OSCILLATOR)
PTA
PTA2/IRQ/KBI2/TCLK
PTA3/RST/KBI3
DDRA
PTA1/AD1/TCH1/KBI1
SYSTEM INTEGRATION
MODULE
PTA4/OSC2/AD2/KBI4
PTA5/OSC1/AD3/KBI5
M68HC08 CPU
SINGLE INTERRUPT
MODULE
BREAK
MODULE
DDRB
PTB
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTB6
PTB7
POWER-ON RESET
MODULE
8-BIT ADC
128 BYTES RAM
MC68HC908QY4 AND MC68HC908QT4
4096 BYTES
MC68HC908QY2, MC68HC908QY1,
MC68HC908QT2, AND MC68HC908QT1:
1536 BYTES
USER FLASH
KEYBOARD INTERRUPT
MODULE
16-BIT TIMER
MODULE
COP
MODULE
VDD
POWER SUPPLY
MONITOR ROM
VSS
RST, IRQ: Pins have internal (about 30K Ohms) pull up
PTA[0:5]: High current sink and source capability
PTA[0:5]: Pins have programmable keyboard interrupt and pull up
PTB[0:7]: Not available on 8-pin devices – MC68HC908QT1, MC68HC908QT2, and MC68HC908QT4
ADC: Not available on the MC68HC908QY1 and MC68HC908QT1
Figure 15-1. Block Diagram Highlighting BRK and MON Blocks
Data Sheet
150
MC68HC908QY/QT Family — Rev. 3
Development Support
MOTOROLA
Development Support
Break Module (BRK)
ADDRESS BUS[15:8]
BREAK ADDRESS REGISTER HIGH
8-BIT COMPARATOR
ADDRESS BUS[15:0]
BKPT
(TO SIM)
CONTROL
8-BIT COMPARATOR
BREAK ADDRESS REGISTER LOW
ADDRESS BUS[7:0]
Figure 15-2. Break Module Block Diagram
Addr.
Register Name
$FE00
Read:
Break Status Register
(BSR) Write:
See page 155.
Reset:
$FE02
Read:
Break Auxiliary Register
(BRKAR) Write:
See page 154.
Reset:
Read:
Break Flag Control
Register (BFCR) Write:
See page 155.
Reset:
$FE03
Read:
Break Address High
Register (BRKH) Write:
See page 154.
Reset:
$FE09
Read:
Break Address Low
Register (BRKL) Write:
See page 154.
Reset:
$FE0A
$FE0B
Read:
Break Status and Control
Register (BRKSCR) Write:
See page 153.
Reset:
Bit 7
6
5
4
3
2
R
R
R
R
R
R
Bit 0
SBSW
Note(1)
R
0
0
0
0
0
0
0
0
BDCOP
0
0
0
0
0
0
0
0
BCFE
R
R
R
R
R
R
R
Bit15
Bit14
Bit13
Bit12
Bit11
Bit10
Bit9
Bit8
0
0
0
0
0
0
0
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
BRKE
BRKA
0
0
0
0
0
0
0
0
R
= Reserved
0
= Unimplemented
1. Writing a 0 clears SBSW.
1
Figure 15-3. Break I/O Register Summary
MC68HC908QY/QT Family — Rev. 3
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When the internal address bus matches the value written in the break address
registers or when software writes a 1 to the BRKA bit in the break status and control
register, the CPU starts a break interrupt by:
•
Loading the instruction register with the SWI instruction
•
Loading the program counter with $FFFC and $FFFD ($FEFC and $FEFD
in monitor mode)
The break interrupt timing is:
•
When a break address is placed at the address of the instruction opcode,
the instruction is not executed until after completion of the break interrupt
routine.
•
When a break address is placed at an address of an instruction operand, the
instruction is executed before the break interrupt.
•
When software writes a 1 to the BRKA bit, the break interrupt occurs just
before the next instruction is executed.
By updating a break address and clearing the BRKA bit in a break interrupt routine,
a break interrupt can be generated continuously.
CAUTION:
A break address should be placed at the address of the instruction opcode. When
software does not change the break address and clears the BRKA bit in the first
break interrupt routine, the next break interrupt will not be generated after exiting
the interrupt routine even when the internal address bus matches the value written
in the break address registers.
15.2.1.1 Flag Protection During Break Interrupts
The system integration module (SIM) controls whether or not module status bits
can be cleared during the break state. The BCFE bit in the break flag control
register (BFCR) enables software to clear status bits during the break state. See
13.8.2 Break Flag Control Register and the Break Interrupts subsection for
each module.
15.2.1.2 TIM During Break Interrupts
A break interrupt stops the timer counter.
15.2.1.3 COP During Break Interrupts
The COP is disabled during a break interrupt with monitor mode when BDCOP bit
is set in break auxiliary register (BRKAR).
Data Sheet
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Break Module (BRK)
15.2.2 Break Module Registers
These registers control and monitor operation of the break module:
•
Break status and control register (BRKSCR)
•
Break address register high (BRKH)
•
Break address register low (BRKL)
•
Break status register (BSR)
•
Break flag control register (BFCR)
15.2.2.1 Break Status and Control Register
The break status and control register (BRKSCR) contains break module enable
and status bits.
Address: $FE0B
Read:
Write:
Reset:
Bit 7
6
BRKE
BRKA
0
0
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented
Figure 15-4. Break Status and Control Register (BRKSCR)
BRKE — Break Enable Bit
This read/write bit enables breaks on break address register matches. Clear
BRKE by writing a 0 to bit 7. Reset clears the BRKE bit.
1 = Breaks enabled on 16-bit address match
0 = Breaks disabled
BRKA — Break Active Bit
This read/write status and control bit is set when a break address match occurs.
Writing a 1 to BRKA generates a break interrupt. Clear BRKA by writing a 0 to
it before exiting the break routine. Reset clears the BRKA bit.
1 = Break address match
0 = No break address match
MC68HC908QY/QT Family — Rev. 3
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15.2.2.2 Break Address Registers
The break address registers (BRKH and BRKL) contain the high and low bytes of
the desired breakpoint address. Reset clears the break address registers.
Address: $FE09
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
0
0
0
0
0
0
0
0
Figure 15-5. Break Address Register High (BRKH)
Address: $FE0A
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
0
Figure 15-6. Break Address Register Low (BRKL)
15.2.2.3 Break Auxiliary Register
The break auxiliary register (BRKAR) contains a bit that enables software to
disable the COP while the MCU is in a state of break interrupt with monitor mode.
Address: $FE02
Read:
Bit 7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Write:
Reset:
Bit 0
BDCOP
0
= Unimplemented
Figure 15-7. Break Auxiliary Register (BRKAR)
BDCOP — Break Disable COP Bit
This read/write bit disables the COP during a break interrupt. Reset clears the
BDCOP bit.
1 = COP disabled during break interrupt
0 = COP enabled during break interrupt
Data Sheet
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Development Support
Break Module (BRK)
15.2.2.4 Break Status Register
The break status register (BSR) contains a flag to indicate that a break caused an
exit from wait mode. This register is only used in emulation mode.
Address: $FE00
Read:
Write:
Bit 7
6
5
4
3
2
R
R
R
R
R
R
Reset:
1
SBSW
Note(1)
Bit 0
R
0
R
= Reserved
1. Writing a 0 clears SBSW.
Figure 15-8. Break Status Register (BSR)
SBSW — SIM Break Stop/Wait
SBSW can be read within the break state SWI routine. The user can modify the
return address on the stack by subtracting one from it.
1 = Wait mode was exited by break interrupt
0 = Wait mode was not exited by break interrupt
15.2.2.5 Break Flag Control Register
The break control register (BFCR) contains a bit that enables software to clear
status bits while the MCU is in a break state.
Address: $FE03
Bit 7
6
5
4
3
2
1
Bit 0
BCFE
R
R
R
R
R
R
R
Read:
Write:
Reset:
0
R
= Reserved
Figure 15-9. Break Flag Control Register (BFCR)
BCFE — Break Clear Flag Enable Bit
This read/write bit enables software to clear status bits by accessing status
registers while the MCU is in a break state. To clear status bits during the break
state, the BCFE bit must be set.
1 = Status bits clearable during break
0 = Status bits not clearable during break
MC68HC908QY/QT Family — Rev. 3
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15.2.3 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power- consumption standby
modes. If enabled, the break module will remain enabled in wait and stop modes.
However, since the internal address bus does not increment in these modes, a
break interrupt will never be triggered.
15.3 Monitor Module (MON)
This subsection describes the monitor module (MON) and the monitor mode entry
methods. The monitor allows debugging and programming of the microcontroller
unit (MCU) through a single-wire interface with a host computer. Monitor mode
entry can be achieved without use of the higher test voltage, VTST, as long as
vector addresses $FFFE and $FFFF are blank, thus reducing the hardware
requirements for in-circuit programming.
Features include:
•
Normal user-mode pin functionality on most pins
•
One pin dedicated to serial communication between MCU and host
computer
•
Standard non-return-to-zero (NRZ) communication with host computer
•
Execution of code in random-access memory (RAM) or FLASH
•
FLASH memory security feature(1)
•
FLASH memory programming interface
•
Use of external 9.8304 MHz oscillator to generate internal frequency of
2.4576 MHz
•
Simple internal oscillator mode of operation (no external clock or high
voltage)
•
Monitor mode entry without high voltage, VTST, if reset vector is blank
($FFFE and $FFFF contain $FF)
•
Standard monitor mode entry if high voltage is applied to IRQ
15.3.1 Functional Description
Figure 15-10 shows a simplified diagram of monitor mode entry.
The monitor module receives and executes commands from a host computer.
Figure 15-11, Figure 15-12, and Figure 15-13 show example circuits used to
enter monitor mode and communicate with a host computer via a standard RS-232
interface.
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or
copying the FLASH difficult for unauthorized users.
Data Sheet
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Development Support
MOTOROLA
Development Support
Monitor Module (MON)
POR RESET
NO
CONDITIONS
FROM Table 15-1
PTA0 = 1,
RESET VECTOR
BLANK?
IRQ = VTST?
YES
PTA0 = 1,
PTA1 = 1, AND
PTA4 = 0?
NO
NO
YES
YES
FORCED
MONITOR MODE
NORMAL
USER MODE
NORMAL
MONITOR MODE
INVALID
USER MODE
HOST SENDS
8 SECURITY BYTES
IS RESET
POR?
YES
NO
YES
ARE ALL
SECURITY BYTES
CORRECT?
ENABLE FLASH
NO
DISABLE FLASH
MONITOR MODE ENTRY
DEBUGGING
AND FLASH
PROGRAMMING
(IF FLASH
IS ENABLED)
EXECUTE
MONITOR CODE
YES
DOES RESET
OCCUR?
NO
Figure 15-10. Simplified Monitor Mode Entry Flowchart
MC68HC908QY/QT Family — Rev. 3
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Data Sheet
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Simple monitor commands can access any memory address. In monitor mode, the
MCU can execute code downloaded into RAM by a host computer while most MCU
pins retain normal operating mode functions. All communication between the host
computer and the MCU is through the PTA0 pin. A level-shifting and multiplexing
interface is required between PTA0 and the host computer. PTA0 is used in a
wired-OR configuration and requires a pullup resistor.
The monitor code has been updated from previous versions of the monitor code to
allow enabling the internal oscillator to generate the internal clock. This addition,
which is enabled when IRQ is held low out of reset, is intended to support serial
communication/programming at 9600 baud in monitor mode by using the internal
oscillator, and the internal oscillator user trim value OSCTRIM (FLASH location
$FFC0, if programmed) to generate the desired internal frequency (3.2 MHz).
Since this feature is enabled only when IRQ is held low out of reset, it cannot be
used when the reset vector is programmed (i.e., the value is not $FFFF) because
entry into monitor mode in this case requires VTST on IRQ. The IRQ pin must
remain low during this monitor session in order to maintain communication.
Table 15-1 shows the pin conditions for entering monitor mode. As specified in the
table, monitor mode may be entered after a power-on reset (POR) and will allow
communication at 9600 baud provided one of the following sets of conditions is
met:
•
If $FFFE and $FFFF do not contain $FF (programmed state):
– The external clock is 9.8304 MHz
– IRQ = VTST
•
If $FFFE and $FFFF contain $FF (erased state):
– The external clock is 9.8304 MHz
– IRQ = VDD (this can be implemented through the internal IRQ pullup)
•
If $FFFE and $FFFF contain $FF (erased state):
– IRQ = VSS (internal oscillator is selected, no external clock required)
The rising edge of the internal RST signal latches the monitor mode. Once monitor
mode is latched, the values on PTA1 and PTA4 pins can be changed.
Once out of reset, the MCU waits for the host to send eight security bytes
(see 15.3.2 Security). After the security bytes, the MCU sends a break signal
(10 consecutive logic 0s) to the host, indicating that it is ready to receive a
command.
Data Sheet
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MOTOROLA
Development Support
Monitor Module (MON)
VDD
VDD
10 kΩ*
VDD
0.1 µF
RST (PTA3)
MAX232
1
1 µF
+
VDD
C1+
VTST
15
C1–
1 µF
1 kΩ
1 µF
1 µF
9.1 V
3
7
10
8
9
10 kΩ*
10 kΩ
+
PTA4
74HC125
5
6
DB9
2
IRQ (PTA2)
VDD
V– 6
5 C2–
10 kΩ*
PTA1
V+ 2
C2+
+
VDD
1 µF
+
4
OSC1 (PTA5)
16
+
3
9.8304 MHz CLOCK
74HC125
3
2
PTA0
4
VSS
1
5
* Value not critical
Figure 15-11. Monitor Mode Circuit (External Clock, with High Voltage)
VDD
N.C.
RST (PTA3)
VDD
0.1 µF
MAX232
1
1 µF
+
16
9.8304 MHz CLOCK
+
3
4
1 µF
C1+
VDD
C1–
C2+
+
5 C2–
1 µF
15
OSC1 (PTA5)
1 µF
+
10 kΩ*
V+ 2
VDD
10 kΩ
74HC125
5
6
+
DB9
2
7
10
3
8
9
2
74HC125
3
N.C.
PTA4
N.C.
IRQ (PTA2)
V– 6
1 µF
PTA1
PTA0
4
VSS
1
5
* Value not critical
Figure 15-12. Monitor Mode Circuit (External Clock, No High Voltage)
MC68HC908QY/QT Family — Rev. 3
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Data Sheet
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VDD
N.C.
RST (PTA3)
VDD
0.1 µF
MAX232
1
1 µF
+
4
C1–
C2+
+
5 C2–
N.C.
1 µF
15
3
IRQ (PTA2)
1 µF
+
PTA1
N.C.
PTA4
N.C.
10 kΩ*
V+ 2
VDD
V– 6
1 µF
10 kΩ
74HC125
5
6
+
DB9
2
OSC1 (PTA5)
16
+
3
1 µF
C1+
VDD
7
10
8
9
74HC125
3
2
PTA0
VSS
4
1
5
* Value not critical
Figure 15-13. Monitor Mode Circuit (Internal Clock, No High Voltage)
15.3.1.1 Normal Monitor Mode
RST and OSC1 functions will be active on the PTA3 and PTA5 pins respectively
as long as VTST is applied to the IRQ pin. If the IRQ pin is lowered (no longer VTST)
then the chip will still be operating in monitor mode, but the pin functions will be
determined by the settings in the configuration registers (see Section 5.
Configuration Register (CONFIG)) when VTST was lowered. With VTST lowered,
the BIH and BIL instructions will read the IRQ pin state only if IRQEN is set in the
CONFIG2 register.
If monitor mode was entered with VTST on IRQ, then the COP is disabled as long
as VTST is applied to IRQ.
Data Sheet
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MOTOROLA
Development Support
Monitor Module (MON)
Table 15-1. Monitor Mode Signal Requirements and Options
Mode
Serial
CommuniRST
Reset
IRQ
cation
(PTA2) (PTA3) Vector
PTA0
Mode
Selection
Communication
Speed
COP
Comments
External
Bus
Clock
Frequency
PTA1 PTA4
Baud
Rate
VTST
VDD
X
1
1
0
Disabled
9.8304
MHz
2.4576
MHz
9600
Provide external
clock at OSC1.
VDD
X
$FFFF
(blank)
1
X
X
Disabled
9.8304
MHz
2.4576
MHz
9600
Provide external
clock at OSC1.
VSS
X
$FFFF
(blank)
1
X
X
Disabled
X
3.2 MHz
(Trimmed)
9600
Internal clock
is active.
User
X
X
Not
$FFFF
X
X
X
Enabled
X
X
X
MON08
Function
[Pin No.]
VTST
[6]
RST
[4]
—
COM
[8]
—
OSC1
[13]
—
—
Normal
Monitor
Forced
Monitor
MOD0 MOD1
[12]
[10]
1. PTA0 must have a pullup resistor to VDD in monitor mode.
2. Communication speed in the table is an example to obtain a baud rate of 9600. Baud rate using external oscillator is bus
frequency / 256 and baud rate using internal oscillator is bus frequency / 335.
3. External clock is a 9.8304 MHz oscillator on OSC1.
4. X = don’t care
5. MON08 pin refers to P&E Microcomputer Systems’ MON08-Cyclone 2 by 8-pin connector.
NC
1
2
GND
NC
3
4
RST
NC
5
6
IRQ
NC
7
8
PTA0
NC
9
10
PTA4
NC
11
12
PTA1
OSC1
13
14
NC
VDD
15
16
NC
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15.3.1.2 Forced Monitor Mode
If entering monitor mode without high voltage on IRQ, then startup port pin
requirements and conditions, (PTA1/PTA4) are not in effect. This is to reduce
circuit requirements when performing in-circuit programming.
NOTE:
If the reset vector is blank and monitor mode is entered, the chip will see an
additional reset cycle after the initial power-on reset (POR). Once the reset vector
has been programmed, the traditional method of applying a voltage, VTST, to IRQ
must be used to enter monitor mode.
If monitor mode was entered as a result of the reset vector being blank, the COP
is always disabled regardless of the state of IRQ.
If the voltage applied to the IRQ is less than VTST, the MCU will come out of reset
in user mode. Internal circuitry monitors the reset vector fetches and will assert an
internal reset if it detects that the reset vectors are erased ($FF). When the MCU
comes out of reset, it is forced into monitor mode without requiring high voltage on
the IRQ pin. Once out of reset, the monitor code is initially executing with the
internal clock at its default frequency.
If IRQ is held high, all pins will default to regular input port functions except for
PTA0 and PTA5 which will operate as a serial communication port and OSC1 input
respectively (refer to Figure 15-11). That will allow the clock to be driven from an
external source through OSC1 pin.
If IRQ is held low, all pins will default to regular input port function except for PTA0
which will operate as serial communication port. Refer to Figure 15-12.
Regardless of the state of the IRQ pin, it will not function as a port input pin in
monitor mode. Bit 2 of the Port A data register will always read 0. The BIH and BIL
instructions will behave as if the IRQ pin is enabled, regardless of the settings in
the configuration register. See Section 5. Configuration Register (CONFIG).
The COP module is disabled in forced monitor mode. Any reset other than a
power-on reset (POR) will automatically force the MCU to come back to the forced
monitor mode.
15.3.1.3 Monitor Vectors
In monitor mode, the MCU uses different vectors for reset, SWI (software interrupt),
and break interrupt than those for user mode. The alternate vectors are in the $FE
page instead of the $FF page and allow code execution from the internal monitor
firmware instead of user code.
NOTE:
Exiting monitor mode after it has been initiated by having a blank reset vector
requires a power-on reset (POR). Pulling RST (when RST pin available) low will
not exit monitor mode in this situation.
Data Sheet
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MOTOROLA
Development Support
Monitor Module (MON)
Table 15-2 summarizes the differences between user mode and monitor mode
regarding vectors.
Table 15-2. Mode Difference
Functions
Modes
Reset
Vector High
Reset
Vector Low
Break
Vector High
Break
Vector Low
SWI
Vector High
SWI
Vector Low
User
$FFFE
$FFFF
$FFFC
$FFFD
$FFFC
$FFFD
Monitor
$FEFE
$FEFF
$FEFC
$FEFD
$FEFC
$FEFD
15.3.1.4 Data Format
Communication with the monitor ROM is in standard non-return-to-zero (NRZ)
mark/space data format. Transmit and receive baud rates must be identical.
START
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP
BIT
NEXT
START
BIT
Figure 15-14. Monitor Data Format
15.3.1.5 Break Signal
A start bit (logic 0) followed by nine logic 0 bits is a break signal. When the monitor
receives a break signal, it drives the PTA0 pin high for the duration of two bits and
then echoes back the break signal.
MISSING STOP BIT
2-STOP BIT DELAY BEFORE ZERO ECHO
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
Figure 15-15. Break Transaction
15.3.1.6 Baud Rate
The monitor communication baud rate is controlled by the frequency of the external
or internal oscillator and the state of the appropriate pins as shown in Table 15-1.
Table 15-1 also lists the bus frequencies to achieve standard baud rates. The
effective baud rate is the bus frequency divided by 256 when using an external
oscillator. When using the internal oscillator in forced monitor mode, the effective
baud rate is the bus frequency divided by 335.
MC68HC908QY/QT Family — Rev. 3
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Data Sheet
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15.3.1.7 Commands
The monitor ROM firmware uses these commands:
•
READ (read memory)
•
WRITE (write memory)
•
IREAD (indexed read)
•
IWRITE (indexed write)
•
READSP (read stack pointer)
•
RUN (run user program)
The monitor ROM firmware echoes each received byte back to the PTA0 pin for
error checking. An 11-bit delay at the end of each command allows the host to send
a break character to cancel the command. A delay of two bit times occurs before
each echo and before READ, IREAD, or READSP data is returned. The data
returned by a read command appears after the echo of the last byte of the
command.
NOTE:
Wait one bit time after each echo before sending the next byte.
FROM
HOST
4
ADDRESS
HIGH
READ
READ
4
1
ADDRESS
HIGH
1
ECHO
Notes:
1 = Echo delay, 2 bit times
2 = Data return delay, 2 bit times
ADDRESS
LOW
4
ADDRESS
LOW
DATA
1
3, 2
4
RETURN
3 = Cancel command delay, 11 bit times
4 = Wait 1 bit time before sending next byte.
Figure 15-16. Read Transaction
FROM
HOST
3
ADDRESS
HIGH
WRITE
WRITE
1
3
ADDRESS
HIGH
1
ADDRESS
LOW
3
ADDRESS
LOW
1
DATA
3
DATA
1
2, 3
ECHO
Notes:
1 = Echo delay, 2 bit times
2 = Cancel command delay, 11 bit times
3 = Wait 1 bit time before sending next byte.
Figure 15-17. Write Transaction
A brief description of each monitor mode command is given in Table 15-3 through
Table 15-8.
Data Sheet
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MOTOROLA
Development Support
Monitor Module (MON)
Table 15-3. READ (Read Memory) Command
Description
Read byte from memory
Operand
2-byte address in high-byte:low-byte order
Data Returned
Returns contents of specified address
Opcode
$4A
Command Sequence
SENT TO MONITOR
ADDRESS ADDRESS ADDRESS
HIGH
HIGH
LOW
READ
READ
ADDRESS
LOW
DATA
ECHO
RETURN
Table 15-4. WRITE (Write Memory) Command
Description
Operand
Data Returned
Opcode
Write byte to memory
2-byte address in high-byte:low-byte order; low byte followed by data
byte
None
$49
Command Sequence
FROM HOST
WRITE
WRITE
ADDRESS
HIGH
ADDRESS
HIGH
ADDRESS
LOW
ADDRESS
LOW
DATA
DATA
ECHO
Table 15-5. IREAD (Indexed Read) Command
Description
Operand
Data Returned
Opcode
Read next 2 bytes in memory from last address accessed
2-byte address in high byte:low byte order
Returns contents of next two addresses
$1A
Command Sequence
FROM HOST
IREAD
IREAD
ECHO
MC68HC908QY/QT Family — Rev. 3
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DATA
DATA
RETURN
Data Sheet
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Table 15-6. IWRITE (Indexed Write) Command
Description
Operand
Data Returned
Opcode
Write to last address accessed + 1
Single data byte
None
$19
Command Sequence
FROM HOST
IWRITE
IWRITE
DATA
DATA
ECHO
A sequence of IREAD or IWRITE commands can access a block of memory
sequentially over the full 64-Kbyte memory map.
Table 15-7. READSP (Read Stack Pointer) Command
Description
Operand
Data Returned
Opcode
Reads stack pointer
None
Returns incremented stack pointer value (SP + 1) in
high-byte:low-byte order
$0C
Command Sequence
FROM HOST
READSP
SP
HIGH
READSP
SP
LOW
ECHO
RETURN
Table 15-8. RUN (Run User Program) Command
Description
Executes PULH and RTI instructions
Operand
None
Data Returned
None
Opcode
$28
Command Sequence
FROM HOST
RUN
RUN
ECHO
Data Sheet
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Development Support
Monitor Module (MON)
The MCU executes the SWI and PSHH instructions when it enters monitor mode.
The RUN command tells the MCU to execute the PULH and RTI instructions.
Before sending the RUN command, the host can modify the stacked CPU registers
to prepare to run the host program. The READSP command returns the
incremented stack pointer value, SP + 1. The high and low bytes of the program
counter are at addresses SP + 5 and SP + 6.
SP
HIGH BYTE OF INDEX REGISTER
SP + 1
CONDITION CODE REGISTER
SP + 2
ACCUMULATOR
SP + 3
LOW BYTE OF INDEX REGISTER
SP + 4
HIGH BYTE OF PROGRAM COUNTER
SP + 5
LOW BYTE OF PROGRAM COUNTER
SP + 6
SP + 7
Figure 15-18. Stack Pointer at Monitor Mode Entry
15.3.2 Security
A security feature discourages unauthorized reading of FLASH locations while in
monitor mode. The host can bypass the security feature at monitor mode entry by
sending eight security bytes that match the bytes at locations $FFF6–$FFFD.
Locations $FFF6–$FFFD contain user-defined data.
NOTE:
Do not leave locations $FFF6–$FFFD blank. For security reasons, program
locations $FFF6–$FFFD even if they are not used for vectors.
During monitor mode entry, the MCU waits after the power-on reset for the host to
send the eight security bytes on pin PTA0. If the received bytes match those at
locations $FFF6–$FFFD, the host bypasses the security feature and can read all
FLASH locations and execute code from FLASH. Security remains bypassed until
a power-on reset occurs. If the reset was not a power-on reset, security remains
bypassed and security code entry is not required. See Figure 15-19.
Upon power-on reset, if the received bytes of the security code do not match the
data at locations $FFF6–$FFFD, the host fails to bypass the security feature. The
MCU remains in monitor mode, but reading a FLASH location returns an invalid
value and trying to execute code from FLASH causes an illegal address reset. After
receiving the eight security bytes from the host, the MCU transmits a break
character, signifying that it is ready to receive a command.
NOTE:
The MCU does not transmit a break character until after the host sends the eight
security bytes.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Development Support
167
Development Support
VDD
4096 + 32 CGMXCLK CYCLES
COMMAND
BYTE 8
BYTE 2
BYTE 1
RST
FROM HOST
PA0
4
BREAK
2
1
COMMAND ECHO
1
BYTE 8 ECHO
Notes:
1 = Echo delay, 2 bit times
2 = Data return delay, 2 bit times
4 = Wait 1 bit time before sending next byte.
1
BYTE 2 ECHO
FROM MCU
4
1
BYTE 1 ECHO
256 BUS CYCLES
(MINIMUM)
Figure 15-19. Monitor Mode Entry Timing
To determine whether the security code entered is correct, check to see if bit 6 of
RAM address $80 is set. If it is, then the correct security code has been entered
and FLASH can be accessed.
If the security sequence fails, the device should be reset by a power-on reset and
brought up in monitor mode to attempt another entry. After failing the security
sequence, the FLASH module can also be mass erased by executing an erase
routine that was downloaded into internal RAM. The mass erase operation clears
the security code locations so that all eight security bytes become $FF (blank).
Data Sheet
168
MC68HC908QY/QT Family — Rev. 3
Development Support
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 16. Electrical Specifications
16.1 Introduction
This section contains electrical and timing specifications.
16.2 Absolute Maximum Ratings
Maximum ratings are the extreme limits to which the microcontroller unit (MCU)
can be exposed without permanently damaging it.
NOTE:
This device is not guaranteed to operate properly at the maximum ratings. Refer to
16.5 5-V DC Electrical Characteristics and 16.9 3-V DC Electrical
Characteristics for guaranteed operating conditions.
Characteristic(1)
Symbol
Value
Unit
Supply voltage
VDD
– 0.3 to + 6.0
V
Input voltage
VIN
VSS – 0.3 to VDD + 0.3
V
VTST
VSS – 0.3 to + 9.1
V
I
±15
mA
IPTA0—IPTA5
±25
mA
Storage temperature
TSTG
– 55 to + 150
°C
Maximum current out of VSS
IMVSS
100
mA
Maximum current into VDD
IMVDD
100
mA
Mode entry voltage, IRQ pin
Maximum current per pin excluding
PTA0–PTA5, VDD, and VSS
Maximum current for pins PTA0–PTA5
1. Voltages references to VSS.
NOTE:
This device contains circuitry to protect the inputs against damage due to high
static voltages or electric fields; however, it is advised that normal precautions be
taken to avoid application of any voltage higher than maximum-rated voltages to
this high-impedance circuit. For proper operation, it is recommended that VIN and
VOUT be constrained to the range VSS ≤ (VIN or VOUT) ≤ VDD. Reliability of
operation is enhanced if unused inputs are connected to an appropriate logic
voltage level (for example, either VSS or VDD.)
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
169
Electrical Specifications
16.3 Functional Operating Range
Characteristic
Operating temperature range
Operating voltage range
Symbol
Value
Unit
Temp.
Code
TA
– 40 to +125
– 40 to +105
– 40 to + 85
°C
M
V
C
VDD
2.7 to 5.5
V
—
16.4 Thermal Characteristics
Characteristic
Symbol
Value
Unit
Thermal resistance
8-pin PDIP
8-pin SOIC
8-pin DFN
16-pin PDIP
16-pin SOIC
16-pin TSSOP
θJA
I/O pin power dissipation
PI/O
User determined
W
Power dissipation(1)
PD
PD = (IDD x VDD)
+ PI/O = K/(TJ + 273°C)
W
Constant(2)
K
Average junction temperature
Maximum junction temperature
105
142
173
76
90
133
PD x (TA + 273°C)
°C/W
+ PD2 x θJA
W/°C
TJ
TA + (PD x θJA)
°C
TJM
150
°C
1. Power dissipation is a function of temperature.
2. K constant unique to the device. K can be determined for a known TA and measured PD. With
this value of K, PD and TJ can be determined for any value of TA.
Data Sheet
170
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
5-V DC Electrical Characteristics
16.5 5-V DC Electrical Characteristics
Characteristic(1)
Symbol
Min
Typ(2)
Max
VDD – 0.4
VDD – 1.5
VDD – 0.8
—
—
—
—
—
—
—
—
50
—
—
—
—
—
—
0.4
1.5
0.8
Unit
Output high voltage
ILoad = –2.0 mA, all I/O pins
ILoad = –10.0 mA, all I/O pins
ILoad = –15.0 mA, PTA0, PTA1, PTA3–PTA5 only
VOH
Maximum combined IOH (all I/O pins)
IOHT
Output low voltage
ILoad = 1.6 mA, all I/O pins
ILoad = 10.0 mA, all I/O pins
ILoad = 15.0 mA, PTA0, PTA1, PTA3–PTA5 only
VOL
Maximum combined IOL (all I/O pins)
IOLT
—
—
50
mA
Input high voltage
PTA0–PTA5, PTB0–PTB7
VIH
0.7 x VDD
—
VDD
V
Input low voltage
PTA0–PTA5, PTB0–PTB7
VIL
VSS
—
0.3 x VDD
V
VHYS
0.06 x VDD
—
—
V
IINJ
–2
—
+2
mA
IINJTOT
–25
—
+25
mA
IIL
–1
±0.1
+1
µA
Capacitance
Ports (as input)
Ports (as input)
CIN
COUT
—
—
—
—
12
8
pF
POR rearm voltage(3)
VPOR
0
—
100
mV
POR rise time ramp rate(4)
RPOR
0.035
—
—
V/ms
Monitor mode entry voltage
VTST
VDD + 2.5
—
9.1
V
Pullup resistors(5)
PTA0–PTA5, PTB0–PTB7
RPU
16
26
36
kΩ
Low-voltage inhibit reset, trip falling voltage
VTRIPF
3.90
4.20
4.50
V
Low-voltage inhibit reset, trip rising voltage
VTRIPR
4.00
4.30
4.60
V
Low-voltage inhibit reset/recover hysteresis
VHYS
—
100
—
mV
Input hysteresis
DC injection current, all ports
Total dc current injection (sum of all I/O)
Ports Hi-Z leakage current
V
mA
V
1. VDD = 4.5 to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted.
2. Typical values reflect average measurements at midpoint of voltage range, 25°C only.
3. Maximum is highest voltage that POR is guaranteed.
4. If minimum VDD is not reached before the internal POR reset is released, the LVI will hold the part in reset until minimum
VDD is reached.
5. RPU is measured at VDD = 5.0 V.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
171
Electrical Specifications
16.6 Typical 5-V Output Drive Characteristics
2.0
VDD-VOH (V)
1.5
5V PTA
1.0
5V PTB
0.5
0.0
0
-5
-10
-15
-20
-25
-30
-35
IOH (mA)
Figure 16-1. Typical 5-Volt Output High Voltage
versus Output High Current (25°C)
2.0
VOL (V)
1.5
5V PTA
5V PTB
1.0
0.5
0.0
0
5
10
15
20
25
30
35
IOL (mA)
Figure 16-2. Typical 5-Volt Output Low Voltage
versus Output Low Current (25°C)
Data Sheet
172
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
5-V Control Timing
16.7 5-V Control Timing
Characteristic(1)
Symbol
Min
Max
Unit
Internal operating frequency
fOP (fBus)
—
8
MHz
Internal clock period (1/fOP)
tcyc
125
—
ns
RST input pulse width low
tRL
100
—
ns
IRQ interrupt pulse width low (edge-triggered)
tILIH
100
—
ns
—
tcyc
tILIL
IRQ interrupt pulse period
(2)
Note
1. VDD = 4.5 to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH; timing shown with respect to 20% VDD and 70% VSS, unless otherwise
noted.
2. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 tcyc.
tRL
RST
tILIL
tILIH
IRQ
Figure 16-3. RST and IRQ Timing
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
173
Electrical Specifications
16.8 5-V Oscillator Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
fINTCLK
—
12.8
—
MHz
fOSCXCLK
1
—
24
MHz
fRCCLK
2
—
12
MHz
fOSCXCLK
dc
—
32
MHz
Crystal load capacitance(3)
CL
—
20
—
pF
Crystal fixed capacitance(3)
C1
—
2 x CL
—
—
C2
—
2 x CL
—
—
RB
1
10
—
MΩ
Internal oscillator frequency
(1)
Crystal frequency, XTALCLK(1)
External RC oscillator frequency, RCCLK(1)
External clock reference frequency
Crystal tuning
(1) (2)
capacitance(3)
Feedback bias resistor
REXT
RC oscillator external resistor
Crystal series damping resistor
fOSCXCLK = 1 MHz
fOSCXCLK = 4 MHz
fOSCXCLK = > 8 MHz
See Figure 16-4
—
—
—
RS
20
10
0
—
—
—
—
kΩ
1. Bus frequency, fOP, is oscillator frequency divided by 4.
2. No more than 10% duty cycle deviation from 50%.
3. Consult crystal vendor data sheet.
14
5 V 25°C
RC FREQUENCY, f RCCLK (MHz)
12
10
8
6
4
2
0
0
10
20
30
40
50
60
R EXT (k Ω)
Figure 16-4. RC versus Frequency (5 Volts @ 25°C)
Data Sheet
174
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
3-V DC Electrical Characteristics
16.9 3-V DC Electrical Characteristics
Characteristic(1)
Symbol
Min
Typ(2)
Max
VDD – 0.3
VDD – 1.0
VDD – 0.8
—
—
—
—
—
—
—
—
50
—
—
—
—
—
—
0.3
1.0
0.8
Unit
Output high voltage
ILoad = –0.6 mA, all I/O pins
ILoad = –4.0 mA, all I/O pins
ILoad = –10.0 mA, PTA0, PTA1, PTA3–PTA5 only
VOH
Maximum combined IOH (all I/O pins)
IOHT
Output low voltage
ILoad = 0.5 mA, all I/O pins
ILoad = 6.0 mA, all I/O pins
ILoad = 10.0 mA, PTA0, PTA1, PTA3–PTA5 only
VOL
Maximum combined IOL (all I/O pins)
IOLT
—
—
50
mA
Input high voltage
PTA0–PTA5, PTB0–PTB7
VIH
0.7 x VDD
—
VDD
V
Input low voltage
PTA0–PTA5, PTB0–PTB7
VIL
VSS
—
0.3 x VDD
V
VHYS
0.06 x VDD
—
—
V
IINJ
–2
—
+2
mA
IINJTOT
–25
—
+25
mA
IIL
–1
±0.1
+1
µA
Capacitance
Ports (as input)
Ports (as input)
CIN
COUT
—
—
—
—
12
8
pF
POR rearm voltage(3)
VPOR
0
—
100
mV
POR rise time ramp rate(4)
RPOR
0.035
—
—
V/ms
Monitor mode entry voltage
VTST
VDD + 2.5
—
VDD + 4.0
V
Pullup resistors(5)
PTA0–PTA5, PTB0–PTB7
RPU
16
26
36
kΩ
Low-voltage inhibit reset, trip falling voltage
VTRIPF
2.40
2.55
2.70
V
Low-voltage inhibit reset, trip rising voltage
VTRIPR
2.50
2.65
2.80
V
Low-voltage inhibit reset/recover hysteresis
VHYS
—
60
—
mV
Input hysteresis
DC injection current, all ports
Total dc current injection (sum of all I/O)
Ports Hi-Z leakage current
V
mA
V
1. VDD = 2.7 to 3.3 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted.
2. Typical values reflect average measurements at midpoint of voltage range, 25°C only.
3. Maximum is highest voltage that POR is guaranteed.
4. If minimum VDD is not reached before the internal POR reset is released, the LVI will hold the part in reset until minimum
VDD is reached.
5. RPU are measured at VDD = 3.0 V
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
175
Electrical Specifications
16.10 Typical 3.0-V Output Drive Characteristics
1.5
VDD-VOH (V)
1.0
3V PTA
3V PTB
0.5
0.0
0
-5
-10
-15
-20
IOH (mA)
Figure 16-5. Typical 3-Volt Output High Voltage
versus Output High Current (25°C)
1.5
VOL (V)
1.0
3V PTA
3V PTB
0.5
0.0
0
5
10
15
20
IOL (mA)
Figure 16-6. Typical 3-Volt Output Low Voltage
versus Output Low Current (25°C)
Data Sheet
176
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
3-V Control Timing
16.11 3-V Control Timing
Characteristic(1)
Symbol
Min
Max
Unit
Internal operating frequency
fOP (fBus)
—
4
MHz
Internal clock period (1/fOP)
tcyc
250
—
ns
RST input pulse width low
tRL
200
—
ns
IRQ interrupt pulse width low (edge-triggered)
tILIH
200
—
ns
—
tcyc
tILIL
IRQ interrupt pulse period
(2)
Note
1. VDD = 2.7 to 3.3 Vdc, VSS = 0 Vdc, TA = TL to TH; timing shown with respect to 20% VDD and 70% VDD, unless otherwise
noted.
2. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 tcyc.
tRL
RST
tILIL
tILIH
IRQ
Figure 16-7. RST and IRQ Timing
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
177
Electrical Specifications
16.12 3-V Oscillator Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
fINTCLK
—
12.8
—
MHz
fOSCXCLK
1
—
16
MHz
fRCCLK
2
—
12
MHz
fOSCXCLK
dc
—
16
MHz
Crystal load capacitance(3)
CL
—
20
—
pF
Crystal fixed capacitance(3)
C1
—
2 x CL
—
—
C2
—
2 x CL
—
—
RB
1
10
—
MΩ
Internal oscillator frequency
(1)
Crystal frequency, XTALCLK(1)
External RC oscillator frequency, RCCLK (1)
External clock reference frequency
Crystal tuning
(1) (2)
capacitance(3)
Feedback bias resistor
REXT
RC oscillator external resistor
Crystal series damping resistor
fOSCXCLK = 1 MHz
fOSCXCLK = 4 MHz
fOSCXCLK = > 8 MHz
See Figure 16-8
—
—
—
RS
10
5
0
—
—
—
—
kΩ
1. Bus frequency, fOP, is oscillator frequency divided by 4.
2. No more than 10% duty cycle deviation from 50%
3. Consult crystal vendor data sheet
12
3 V 25°C
RC FREQUENCY, f
RCCLK (MHz)
10
8
6
4
2
0
0
10
20
30
40
50
60
R EXT (k Ω)
Figure 16-8. RC versus Frequency (3 Volts @ 25°C)
Data Sheet
178
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
Supply Current Characteristics
16.13 Supply Current Characteristics
Voltage
Bus
Frequency
(MHz)
Symbol
Typ(2)
Max
Unit
Run Mode VDD supply current(3)
5.0
3.0
3.2
3.2
RIDD
6.0
2.5
7.0
3.2
mA
Wait Mode VDD supply current(4)
5.0
3.0
3.2
3.2
WIDD
1.0
0.67
1.5
1.0
mA
mA
0.04
—
—
7
125
1.0
2.0
5.0
—
—
0.02
—
—
5
100
0.5
1.0
4.0
—
—
Characteristic(1)
Stop Mode VDD supply current(5)
–40 to 85°C
–40 to 105°C
–40 to 125°C
25°C with auto wakeup enabled
Incremental current with LVI enabled at 25°C
Stop Mode VDD supply current(5)
–40 to 85°C
–40 to 105°C
–40 to 125°C
25°C with auto wakeup enabled
Incremental current with LVI enabled at 25°C
5.0
3.0
SIDD
SIDD
µA
µA
1. VSS = 0 Vdc, TA = TL to TH, unless otherwise noted.
2. Typical values reflect average measurements at 25°C only.
3. Run (operating) IDD measured using trimmed internal oscillator, ADC off, all other modules enabled. All pins configured as
inputs and tied to 0.2 V from rail.
4. Wait IDD measured using trimmed internal oscillator, ADC off, all other modules enabled. All pins configured as inputs and
tied to 0.2 V from rail.
5. Stop IDD measured with all pins tied to 0.2 V or less from rail. No dc loads. On the 8-pin versions, port B is configured as
inputs with pullups enabled.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
179
Electrical Specifications
14
12
IDD (mA)
10
Crystal w/o ADC
8
Crystal w/ ADC
6
4
Internal Osc w/o
ADC
2
Internal Osc w/
ADC
0
0
1
2
3
4
5
6
7
Bus Frequency (MHz)
Figure 16-9. Typical 5-Volt Run Current
versus Bus Frequency (25°C)
4
3
IDD (mA)
Crystal w/o ADC
2
Crystal w/ ADC
Internal Osc w/o
ADC
1
Internal Osc w/
ADC
0
0
1
2
3
4
5
Bus Frequency (MHz)
Figure 16-10. Typical 3-Volt Run Current
versus Bus Frequency (25°C)
Data Sheet
180
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
Analog-to-Digital Converter Characteristics
16.14 Analog-to-Digital Converter Characteristics
Characteristic
Symbol
Min
Max
Unit
Comments
Supply voltage
VDDAD
2.7
(VDD min)
5.5
(VDD max)
V
—
Input voltages
VADIN
VSS
VDD
V
—
Resolution
(1 LSB)
RES
10.5
21.5
mV
—
Absolute accuracy
(Total unadjusted error)
ETUE
—
± 1.5
LSB
Includes quantization
ADC internal clock
fADIC
0.5
1.048
MHz
tADIC = 1/fADIC,
tested only at 1 MHz
Conversion range
VAIN
VSS
VDD
V
—
Power-up time
tADPU
16
—
tADIC cycles
tADIC = 1/fADIC
Conversion time
tADC
16
17
tADIC cycles
tADIC = 1/fADIC
Sample time(1)
tADS
5
—
tADIC cycles
tADIC = 1/fADIC
Zero input reading(2)
ZADI
00
01
Hex
VIN = VSS
Full-scale reading(3)
FADI
FE
FF
Hex
VIN = VDD
Input capacitance
CADI
—
8
pF
Not tested
IIL
—
±1
µA
—
mA
mA
Enabled
Enabled
Input leakage(3)
ADC supply current
VDD = 3 V
VDD = 5 V
IADAD
Typical = 0.45
Typical = 0.65
1. Source impedances greater than 10 kΩ adversely affect internal RC charging time during input sampling.
2. Zero-input/full-scale reading requires sufficient decoupling measures for accurate conversions.
3. The external system error caused by input leakage current is approximately equal to the product of R source and input
current.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
181
Electrical Specifications
16.15 Timer Interface Module Characteristics
Characteristic
Symbol
Min
Max
Unit
tTH, tTL
2
—
tcyc
tTLTL
Note(1)
—
tcyc
tTCL, tTCH
tcyc + 5
—
ns
Timer input capture pulse width
Timer input capture period
Timer input clock pulse width
1. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 tcyc.
tTLTL
tTH
INPUT CAPTURE
RISING EDGE
tTLTL
tTL
INPUT CAPTURE
FALLING EDGE
tTLTL
tTH
tTL
INPUT CAPTURE
BOTH EDGES
tTCH
TCLK
tTCL
Figure 16-11. Timer Input Timing
Data Sheet
182
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Electrical Specifications
Memory Characteristics
16.16 Memory Characteristics
Characteristic
Symbol
Min
Typ
Max
Unit
VRDR
1.3
—
—
V
—
1
—
—
MHz
fRead(1)
0
—
8M
Hz
FLASH page erase time
<1 k cycles
>1 k cycles
tErase
0.9
3.6
1
4
1.1
5.5
ms
FLASH mass erase time
tMErase
4
—
—
ms
FLASH PGM/ERASE to HVEN setup time
tNVS
10
—
—
µs
FLASH high-voltage hold time
tNVH
5
—
—
µs
FLASH high-voltage hold time (mass erase)
tNVHL
100
—
—
µs
FLASH program hold time
tPGS
5
—
—
µs
FLASH program time
tPROG
30
—
40
µs
FLASH return to read time
tRCV(2)
1
—
—
µs
FLASH cumulative program hv period
tHV(3)
—
—
4
ms
FLASH endurance(4)
—
10 k
100 k
—
Cycles
FLASH data retention time(5)
—
15
100
—
Years
RAM data retention voltage
FLASH program bus clock frequency
FLASH read bus clock frequency
1. fRead is defined as the frequency range for which the FLASH memory can be read.
2. tRCV is defined as the time it needs before the FLASH can be read after turning off the high voltage charge pump, by
clearing HVEN to 0.
3. tHV is defined as the cumulative high voltage programming time to the same row before next erase.
tHV must satisfy this condition: tNVS + tNVH + tPGS + (tPROG x 32) ≤ tHV maximum.
4. Typical endurance was evaluated for this product family. For additional information on how Motorola defines Typical
Endurance, please refer to Engineering Bulletin EB619.
5. Typical data retention values are based on intrinsic capability of the technology measured at high temperature and de-rated
to 25°C using the Arrhenius equation. For additional information on how Motorola defines Typical Data Retention, please
refer to Engineering Bulletin EB618.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Electrical Specifications
183
Electrical Specifications
Data Sheet
184
MC68HC908QY/QT Family — Rev. 3
Electrical Specifications
MOTOROLA
Data Sheet — MC68HC908QY/QT Family
Section 17. Ordering Information and Mechanical Specifications
17.1 Introduction
This section contains order numbers for the MC68HC908QY1, MC68HC908QY2,
MC68HC908QY4, MC68HC908QT1, MC68HC908QT2, and MC69HC908QT4.
Dimensions are given for:
•
8-pin plastic dual in-line package (PDIP)
•
8-pin small outline integrated circuit (SOIC) package
•
8-pin dual flat no lead (DFN) package
•
16-pin PDIP
•
16-pin SOIC
•
16-pin thin shrink small outline package (TSSOP)
17.2 MC Order Numbers
Table 17-1. MC Order Numbers
MC Order Number
ADC
FLASH Memory
Package
MC68HC908QY1
—
1536 bytes
MC68HC908QY2
Yes
1536 bytes
MC68HC908QY4
Yes
4096 bytes
16-pins
PDIP, SOIC,
and TSSOP
MC68HC908QT1
—
1536 bytes
MC68HC908QT2
Yes
1536 bytes
MC68HC908QT4
Yes
4096 bytes
8-pins
PDIP, SOIC,
and DFN
Temperature and package designators:
C = –40°C to +85°C
V = –40°C to +105°C
M = –40°C to +125°C
P = Plastic dual in-line package (PDIP)
DW = Small outline integrated circuit package (SOIC)
DT = Thin shrink small outline package (TSSOP)
FQ = Dual flat no lead (DFN)
MC68HC908QY1XXX
FAMILY
PACKAGE DESIGNATOR
TEMPERATURE RANGE
Figure 17-1. Device Numbering System
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
Data Sheet
Ordering Information and Mechanical Specifications
185
Ordering Information and Mechanical Specifications
17.3 8-Pin Plastic Dual In-Line Package (Case #626)
8
NOTES:
1. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.
2. PACKAGE CONTOUR OPTIONAL (ROUND OR
SQUARE CORNERS).
3. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
5
-B1
4
DIM
A
B
C
D
F
G
H
J
K
L
M
N
F
-A-
NOTE 2
L
C
J
-TN
SEATING
PLANE
D
G
H
0.13 (0.005)
M
T A
M
B
INCHES
MIN MAX
0.370 0.400
0.240 0.260
0.155 0.175
0.015 0.020
0.040 0.070
0.100 BSC
0.030 0.050
0.008 0.012
0.115 0.135
0.300 BSC
--10 °
0.030 0.040
STYLE 1:
1.
AC IN
2.
DC + IN
3.
DC - IN
4.
AC IN
5.
GROUND
6.
OUTPUT
7.
AUXILIARY
8.
VCC
M
K
MILLIMETERS
MIN
MAX
9.40 10.16
6.10
6.60
3.94
4.45
0.38
0.51
1.02
1.78
2.54 BSC
0.76
1.27
0.20
0.30
2.92
3.43
7.62 BSC
--10 °
0.76
1.01
M
17.4 8-Pin Small Outline Integrated Circuit Package (Case #968)
8
LE
5
Q1
E HE
M×
1
4
L
Z
DETAIL P
D
e
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER
3. DIMENSION D AND E DO NOT INCLUDE MOLD
FLASH OR PROTRUSIONS AND ARE
MEASURED AT THE PARTING LINE. MOLD
FLASH OR PROTRUSIONS SHALL NOT
EXCEED 0.15 (0.006) PER SIDE.
4. TERMINAL NUMBERS ARE SHOWN FOR
REFERENCE ONLY.
5. THE LEAD WIDTH DIMENSION (b) DOES NOT
INCLUDE DAMBAR PROTUSION. ALLOWABLE
DAMBAR PROTRUSION SHALL BE 0.08 (0.003)
TOTAL IN EXCESS OF THE LEAD WIDTH
DIMENSION AT MAXIMUM MATERIAL
CONDITION. DAMBAR CANNOT BE LOCATED
ON THE LOWER RADIUS OR THE FOOT
MINIMUM SPACE BETWEEN PROTRUSIONS
AND ADJACENT LEAD TO BE 0.46 (0.018).
A1
A
P
b
0.13 (0.005)
c
M
0.10 (0.004)
DIM
A
A1
b
c
D
E
e
HE
L
LE
M
Q1
Z
Data Sheet
186
MILLIMETERS
MIN
MAX
--2.05
0.05
0.20
0.35
0.50
0.18
0.27
5.10
5.50
5.10
5.45
1.27 BSC
7.40
8.20
0.50
0.85
1.10
1.50
0°
10°
0.70
0.90
--0.94
INCHES
MIN MAX
--- 0.081
0.002 0.008
0.014 0.020
0.007 0.011
0.201 0.217
0.201 0.215
0.050 BSC
0.291 0.323
0.020 0.033
0.043 0.059
0°
10°
0.028 0.035
--- 0.037
MC68HC908QY/QT Family — Rev. 3
Ordering Information and Mechanical Specifications
MOTOROLA
Ordering Information and Mechanical Specifications
8-Pin Dual Flat No Lead (DFN) Package (Case #1452)
17.5 8-Pin Dual Flat No Lead (DFN) Package (Case #1452)
0.1 C
4
A
0.1 C
2X
8
0.1 C
5
1.0 1.00
0.8 0.75
2X
0.05 C
4
(0.35)
0.05
0.00
4
(0.8)
C
SEATING PLANE
DETAIL G
VIEW ROTATED 90 o CLOCKWISE
1
4
0.3
0.2
PIN 1
INDEX AREA
B
G
M
0.3
0.2
M
DETAIL M
BACKSIDE PIN 1 INDEX
0.1 C A B
DETAIL M
PIN 1 INDEX
1
3.5
3.4
EXPOSED DIE
ATTACH PAD
4
3.05
2.95
0.1 C A B
2.55
2.45
0.1 C A B
0.4
6X
DETAIL N
N
8X
0.5
0.4
8
5
8X
VIEW M-M
0.35
0.25
0.1
0.05
M
C A B
M
C
8X
0.065
0.015
NOTES:
1. ALL DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND TOLERANCES PER
ASME Y14.5M, 1994.
3. THE COMPLETE JEDEC DESIGNATOR FOR THIS
PACKAGE IS: HP-VFDFP-N.
4. COPLANARITY APPLIES TO LEADS AND DIE ATTACH
PAD.
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
0.8
Data Sheet
Ordering Information and Mechanical Specifications
187
Ordering Information and Mechanical Specifications
17.6 16-Pin Plastic Dual In-Line Package (Case #648D)
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
4. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
5. MOLD FLASH OR PROTRUSIONS SHALL NOT
EXCEED 0.25 (0.010).
6. ROUNDED CORNERS OPTIONAL.
-A16
9
-B1
8
F
L
C
S
-T-
SEATING
PLANE
K
H
G
M
J
D 16 PL
0.25 (0.010)
M
T B
S
A
S
DIM
A
B
C
D
F
G
H
J
K
L
M
S
INCHES
MILLIMETERS
MIN
MAX
MIN MAX
0.740 0.760 18.80 19.30
0.245 0.260
6.23
6.60
0.145 0.175
3.69
4.44
0.015 0.021
0.39
0.53
0.050 0.070
1.27
1.77
0.100 BSC
2.54 BSC
0.050 BSC
1.27 BSC
0.008 0.015
0.21
0.38
0.120 0.140
3.05
3.55
0.295 0.305
7.50
7.74
0°
10°
0°
10°
0.015 0.035
0.39
0.88
17.7 16-Pin Small Outline Integrated Circuit Package (Case #751G)
A
D
q
9
1
8
h X 45 °
H
E
0.25
8X
M
B
M
16
16X
M
14X
e
B
B
T A
S
B
S
A1
L
A
0.25
NOTES:
1. DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND
TOLERANCES PER ASME Y14.5M, 1994.
3. DIMENSIONS D AND E DO NOT INLCUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 PER
SIDE.
5. DIMENSION B DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 TOTAL IN
EXCESS OF THE B DIMENSION AT MAXIMUM
MATERIAL CONDITION.
SEATING
PLANE
T
C
Data Sheet
188
MILLIMETERS
DIM MIN
MAX
A
2.35
2.65
A1 0.10
0.25
B
0.35
0.49
C
0.23
0.32
D 10.15 10.45
E
7.40
7.60
e
1.27 BSC
H 10.05 10.55
h
0.25
0.75
L
0.40
1.00
q
0°
7°
MC68HC908QY/QT Family — Rev. 3
Ordering Information and Mechanical Specifications
MOTOROLA
Ordering Information and Mechanical Specifications
16-Pin Thin Shrink Small Outline Package (Case #948F)
17.8 16-Pin Thin Shrink Small Outline Package (Case #948F)
16X K REF
0.10 (0.004) M T U
0.15 (0.006) T U
V
S
S
S
K
K1
2X
L/2
16
9
J1
B
-U-
L
SECTION N-N
J
PIN 1
IDENT.
8
1
N
0.15 (0.006) T U
S
0.25 (0.010)
A
-V-
M
NOTES:
4. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
5. CONTROLLING DIMENSION: MILLIMETER.
6. DIMENSION A DOES NOT INCLUDE MOLD
FLASH. PROTRUSIONS OR GATE BURRS.
MOLD FLASH OR GATE BURRS SHALL NOT
EXCEED 0.15 (0.006) PER SIDE.
7. DIMENSION B DOES NOT INCLUDE
INTERLEAD FLASH OR PROTRUSION.
INTERLEAD FLASH OR PROTRUSION SHALL
NOT EXCEED
0.25 (0.010) PER SIDE.
8. DIMENSION K DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.08 (0.003) TOTAL
IN EXCESS OF THE K DIMENSION AT
MAXIMUM MATERIAL CONDITION.
9. TERMINAL NUMBERS ARE SHOWN FOR
REFERENCE ONLY.
10. DIMENSION A AND B ARE TO BE
DETERMINED AT DATUM PLANE -W-.
N
F
DETAIL E
-W-
C
0.10 (0.004)
-T- SEATING
PLANE
H
D
DETAIL E
G
MC68HC908QY/QT Family — Rev. 3
MOTOROLA
DIM
A
B
C
D
F
G
H
J
J1
K
K1
L
M
MILLIMETERS
MIN
MAX
4.90
5.10
4.30
4.50
--1.20
0.05
0.15
0.50
0.75
0.65 BSC
0.18
0.28
0.09
0.20
0.09
0.16
0.19
0.30
0.19
0.25
6.40 BSC
0°
8°
INCHES
MIN MAX
0.193 0.200
0.169 0.177
--- 0.047
0.002 0.006
0.020 0.030
0.026 BSC
0.007 0.011
0.004 0.008
0.004 0.006
0.007 0.012
0.007 0.010
0.252 BSC
0°
8°
Data Sheet
Ordering Information and Mechanical Specifications
189
Ordering Information and Mechanical Specifications
Data Sheet
190
MC68HC908QY/QT Family — Rev. 3
Ordering Information and Mechanical Specifications
MOTOROLA
HOW TO REACH US:
USA/EUROPE/LOCATIONS NOT LISTED:
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P.O. Box 5405
Denver, Colorado 80217
1-800-521-6274 or 480-768-2130
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SPS, Technical Information Center
3-20-1, Minami-Azabu, Minato-ku
Tokyo 106-8573, Japan
81-3-3440-3569
ASIA/PACIFIC:
Motorola Semiconductors H.K. Ltd.
Silicon Harbour Centre
2 Dai King Street
Tai Po Industrial Estate
Tai Po, N.T., Hong Kong
852-26668334
HOME PAGE:
http://motorola.com/semiconductors
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© Motorola Inc. 2004
MC68HC908QY4/D
Rev. 3.0
1/2004