Freescale MC68CK338 32-bit modular microcontroller Datasheet

MOTOROLA
Freescale Semiconductor, Inc.
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SEMICONDUCTOR
TECHNICAL DATA
MC68CK338
Technical Summary
32-Bit Modular Microcontroller
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1 Introduction
The MC68CK338, a highly-integrated 32-bit microcontroller, combines high-performance data manipulation capabilities with powerful peripheral subsystems. The MCU is built up from standard modules that
interface through a common intermodule bus (IMB). Standardization facilitates rapid development of
devices tailored for specific applications.
The MCU incorporates a low-power 32-bit CPU (CPU32L), a low-power system integration module
(SIML), a queued serial module (QSM), and a configurable timer module 6 (CTM6).
The MCU clock can either be synthesized from an external reference or input directly. Operation with a
32.768 kHz reference frequency is standard. The maximum system clock speed is 14.4 MHz. System
hardware and software allow changes in clock rate during operation. Because MCU operation is fully
static, register and memory contents are not affected by clock rate changes.
High-density complementary metal-oxide semiconductor (HCMOS) architecture and 3V nominal operation make the basic power consumption of the MCU low. Power consumption can be minimized by
either stopping the system clock, or alternatively, stopping the system clock only at the CPU32L, and
allowing the other modules to continue operation. The CPU32 instruction set includes a low-power stop
(LPSTOP) command that allows either of these power saving modes.
The CTM6 includes new features such as a port I/O submodule, a 64-byte RAM submodule and a real
time clock submodule.
Refer to the Motorola Microcontroller Technologies Group Web page at http://www.mcu.sps.mot.com
for the most current listing of device errata and customer information.
Table 1 Ordering Information
Package Type
Frequency
(MHz)
Voltage
Temperature
Package
Order
Quantity
Order Number
144–Pin TQFP
14.4 MHz
2.7V to 3.6V
– 40 to + 85 °C
2 pc tray
60 pc tray
300 pc tray
SPMC68CK338CPV14
MC68CK338CPV14
MC68CK338CPV14B1
RoHS-compliant and/or Pb- free versions of Freescale products have the functionality
and electrical characteristics of their non-RoHS-compliant and/or non-Pb- free
counterparts. For further information, see http://www.freescale.com or contact your
Freescale sales representative.
For information on Freescale.s Environmental Products program, go to
http://www.freescale.com/epp.
This document contains information on a new product. Specifications and information herein are subject to change without notice.
© MOTOROLA INC., 1996
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TABLE OF CONTENTS
Section
1
Introduction
1.1
1.2
1.3
1.4
1.5
2
2.1
2.2
2.3
2.4
2.5
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3
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4
4.1
4.2
4.3
4.4
4.5
4.6
4.7
5
5.1
5.2
5.3
5.4
5.5
5.6
6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
6.15
7
Page
1
Features ......................................................................................................................................3
Block Diagram .............................................................................................................................4
Pin Assignments ..........................................................................................................................5
Address Map ...............................................................................................................................6
Intermodule Bus ..........................................................................................................................6
Signal Descriptions
7
Pin Characteristics ......................................................................................................................7
MCU Power Connections ............................................................................................................8
MCU Driver Types .......................................................................................................................8
Signal Characteristics ..................................................................................................................9
Signal Function ..........................................................................................................................10
Low-Power System Integration Module
12
Overview ...................................................................................................................................12
System Configuration Block ......................................................................................................14
System Clock ............................................................................................................................16
System Protection Block ...........................................................................................................22
External Bus Interface ...............................................................................................................26
Chip-Selects ..............................................................................................................................30
General-Purpose Input/Output ..................................................................................................38
Resets .......................................................................................................................................41
Interrupts ...................................................................................................................................44
Factory Test Block .....................................................................................................................47
Low-Power Central Processor Unit
48
Overview ...................................................................................................................................48
Programming Model ..................................................................................................................48
Status Register ..........................................................................................................................50
Data Types ................................................................................................................................51
Addressing Modes .....................................................................................................................51
Instruction Set Summary ...........................................................................................................51
Background Debugging Mode ...................................................................................................56
Queued Serial Module
57
Overview ...................................................................................................................................57
Address Map .............................................................................................................................58
Pin Function ..............................................................................................................................59
QSM Registers ..........................................................................................................................59
QSPI Submodule .......................................................................................................................64
SCI Submodule .........................................................................................................................72
Configurable Timer Module 6
78
Overview ...................................................................................................................................78
Address Map .............................................................................................................................80
Time Base Bus System .............................................................................................................82
Bus Interface Unit Submodule (BIUSM) ....................................................................................84
Counter Prescaler Submodule (CPSM) ....................................................................................85
Clock Sources for Counter Submodules ...................................................................................87
Free-Running Counter Submodule (FCSM) ..............................................................................87
Modulus Counter Submodule (MCSM) .....................................................................................90
Single Action Submodule (SASM) .............................................................................................93
Double-Action Submodule (DASM) ...........................................................................................97
Real-Time Clock Submodule (RTCSM) with Low-Power Oscillator ........................................104
Parallel Port I/O Submodule (PIOSM) .....................................................................................107
Static RAM Submodule (RAMSM) ..........................................................................................108
RTCSM and RAMSM Standby Operation ...............................................................................108
CTM6 Interrupts ......................................................................................................................109
Electrical Characteristics
111
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1.1 Features
• Modular Architecture
• Low-Power Central Processing Unit (CPU32L)
— Virtual memory implementation
— Loop mode of instruction execution
— Improved exception handling for controller applications
— Table lookup and interpolate instruction
— CPU-only LPSTOP operation/normal MCU LPSTOP operation
• Low-Power System Integration Module (SIML)
— External bus support
— Twelve programmable chip-select outputs
— System protection logic
— On-chip PLL for system clock
— Watchdog timer, clock monitor, and bus monitor
— Expanded LPSTOP operation
• Queued Serial Module (QSM)
— Enhanced serial communication interface (SCI)
— Queued serial peripheral interface (QSPI)
— Dual function I/O ports
• Configurable Timer Module 6 (CTM6)
— One bus interface unit submodule (BIUSM)
— One counter prescaler submodule (CPSM)
— Three modulus counter submodules (MCSM)
— One free-running counter submodule (FCSM)
— Eleven double action submodules (DASM)
— Four (eight channels) single action submodules (SASM)
— One real time clock submodule (RTCSM)
— One port I/O submodule (PIOSM)
— Two 32-byte RAM submodules (RAMSM)
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1.2 Block Diagram
CTS14A
CTS14B
CTS18A
CTS18B
CTS24A
CTS24B
FC2
FC1
FC0
CTM6
CTD[10:4]
CTD[29:26]
CTM31L
64 BYTES
2 RAMSM
ADDR23/CS10
PC6/ADDR22/CS9
PC5/ADDR21/CS8
PC4/ADDR20/CS7
PC3/ADDR19/CS6
PC2/FC2/CS5
PC1/FC1/CS4
PC0/FC0/CS3
BGACK/CS2
BG/CS1
BR/CS0
ADDR[23:19]
1 PIOSM
CTIO[5:0]
CTD[10:4]
ADDR[23:0]
ADDR[18:0]
SIZ1
SIZ0
AS
DS
RMC
AVEC
DSACK1
DSACK0
PE7/SIZ1
PE6/SIZ0
PE5/AS
PE4/DS
PE3/RMC
PE2/AVEC
PE1/DSACK1
PE0/DSACK0
1 RTCSM
IMB
CONTROL
PORT E
CTM31L
11 DASM
4 SASM
CTD[29:26]
CSBOOT
BR
BG
BGACK
CS[10:0]
3 MCSM
PQS7/TXD
PQS6/PCS3
PQS5/PCS2
PQS4/PCS1
PQS3/PCS0/SS
PQS2/SCK
PQS1/MOSI
PQS0/MISO
PORTQS
CONTROL
RXD
EBI
SS
TXD
PCS3
PCS2
PCS1
PCS0
SCK
MOSI
MISO
DATA[15:0]
QSM
DATA[15:0]
R/W
RESET
HALT
BERR
CPU32L
CONTROL
PORT F
IRQ[7:1]
MODCLK
BKPT
IFETCH
IPIPE
DSI
DSO
DSCLK
FREEZE
TSC
QUOT
CONTROL
TEST
BKPT/DSCLK
IFETCH/DSI
IPIPE/DSO
PF7/IRQ7
PF6/IRQ6
PF5/IRQ5
PF4/IRQ4
PF3/IRQ3
PF2/IRQ2
PF1/IRQ1
PF0/MODCLK
CLKOUT
XTAL
EXTAL
XFC
VDDSYN
CLOCK
CONTROL
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CTIO[5:0]
PORT CT
CTS14A
CTS14B
CTS18A
CTS18B
CTS24A
CTS24B
CHIP
SELECTS
1 FCSM
CONTROL
PORT C
VRTC
VSSRTCOSC
EXRTC
XRTC
VSSRTCOSC
VRTC
VSSRTCOSC
EXRTC
XRTC
VSSRTCOSC
TSC
FREEZE/QUOT
338 BLOCK
Figure 1 MC68CK338 Block Diagram
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
MC68CK338
108
107
106
104
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
VDDE
NC
NC
NC
FC0/CS3
BGACK/CS2
BG/CS1
BR/CS0
CSBOOT
DATA0
DATA1
DATA2
DATA3
DATA4
DATA5
DATA6
DATA7
VSSI
DATA8
DATA9
DATA10
DATA11
DATA12
DATA13
DATA14
DATA15
ADDR0
DSACK0
DSACK1
AVEC
RMC
DS
AS
SIZ0
SIZ1
VDDE
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
VDDE
CTD6
CTD7
CTD8
CTD9
CTD10
CTIO1
CTIO0
VRTC
MISO
MOSI
SCK
PCS0/SS
PCS1
PCS2
PCS3
TXD
VSSI
RXD
ADDR1
ADDR2
ADDR3
ADDR4
ADDR5
ADDR6
ADDR7
ADDR8
ADDR9
ADDR10
ADDR11
ADDR12
ADDR13
ADDR14
ADDR15
ADDR16
VDDE
NC
NC
NC
VSSE
ADDR17
ADDR18
IPIPE/DSO
IFETCH/DSI
BKPT/DSCLK
TSC
FREEZE/QUOT
VSSI
XTAL
VDDSYN
EXTAL
VDDI
XFC
VDDE
CLKOUT
VSSE
RESET
HALT
BERR
IRQ7
IRQ6
IRQ5
IRQ4
IRQ3
IRQ2
IRQ1
MODCLK
R/W
VSSE
NC
NC
NC
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144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
NC
VSSE
CTD5
CTD4
VSSRTCOSC
XRTC
EXRTC
VSSRTCOSC
CTIO2
CTIO3
CTS14B
CTS14A
CTIO4
CTIO5
CTS18B
CTS18A
CTS24B
CTS24A
VSSI
VDDI
CTD29
CTD28
CTD27
CTD26
CTM31L
ADDR23/CS10
ADDR22/CS9
ADDR21/CS8
ADDR20/CS7
ADDR19/CS6
FC2/CS5
FC1/CS4
VSSE
NC
NC
NC
1.3 Pin Assignments
338 144-PIN QFP
Figure 2 MC68CK338 Pin Assignments
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1.4 Address Map
Figure 3 shows a map of the MCU internal addresses. Unimplemented blocks are mapped externally.
$YFF400
CTM6
512 BYTES
$YFF5FF
$YFFA00
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SIML
128 BYTES
$YFFA7F
$YFFC00
QSM
512 BYTES
$YFFDFF
Y = M111, WHERE M IS THE STATE OF THE MODULE MAPPING (MM) BIT IN THE SIML CONFIGURATION REGISTER.
338 ADDRESS MAP
Figure 3 MC68CK338 Address Map
1.5 Intermodule Bus
The IMB is a standardized bus developed to facilitate design and operation of modular microcontrollers.
It contains circuitry that supports exception processing, address space partitioning, multiple interrupt
levels, and vectored interrupts. The standardized modules in the MCU communicate with one another
and with external components via the IMB. The IMB uses 24 address lines and 16 data lines.
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2 Signal Descriptions
2.1 Pin Characteristics
Table 2 shows MCU pins and their characteristics. All inputs detect CMOS logic levels. All inputs can
be put in a high-impedance state, but the method of doing this differs depending upon pin function. Refer to Table 4 for a description of output drivers. An entry in the discrete I/O column of Table 2 indicates
that a pin has an alternate I/O function. The port designation is given when it applies. Refer to Figure
1 for information about port organization.
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Table 2 MCU Pin Characteristics
Pin
Mnemonic
Output
Driver
Input
Synchronized
Input
Hysteresis
Discrete
I/O
Port
Designation
ADDR23/CS10
A
Yes
No
—
—
ADDR[22:19]/CS[9:6]
A
Yes
No
O
PC[6:3]
ADDR[18:0]
A
Yes
No
—
—
AS
B
Yes
No
I/O
PE5
AVEC
B
Yes
No
I/O
PE2
BERR
B
Yes1
No
—
—
BG/CS1
B
—
—
—
—
BGACK/CS2
B
Yes
No
—
—
BKPT/DSCLK
—
Yes
Yes
—
—
BR/CS0
B
Yes
No
—
—
CLKOUT
A
—
—
—
—
CSBOOT
B
—
—
—
—
CTD[29:26]
Ao
Yes
Yes
I/O
—
CTD[10:4]
Ao
Yes
Yes
I/O
—
CTIO[5:0]
A
Yes
Yes
I/O
—
CTM31L
A
Yes
Yes
I
—
CTS24[B:A]
A
Yes
Yes
I/O
—
CTS18[B:A]
A
Yes
Yes
I/O
—
CTS14[B:A]
A
Yes
Yes
I/O
—
2
DATA[15:0]
Aw
Yes
No
—
—
DS
B
Yes
No
I/O
PE4
DSACK[1:0]
B
Yes
No
I/O
PE[1:0]
DSI/IFETCH
A
Yes
Yes
—
—
DSO/IPIPE
A
—
—
—
—
EXRTC
—
—
Yes
—
—
EXTAL
—
—
Yes
—
—
FC[2:0]/CS[5:3]
A
Yes
No
O
PC[2:0]
FREEZE/QUOT
A
—
—
—
—
HALT
Bo
Yes1
No
—
—
IRQ[7:1]
B
Yes
Yes
I/O
PF[7:1]
MISO
Bo
Yes2
Yes
I/O
PQS0
MODCLK
B
Yes2
No
I/O
PF0
MOSI
Bo
Yes2
Yes
I/O
PQS1
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Table 2 MCU Pin Characteristics (Continued)
Pin
Mnemonic
Output
Driver
Input
Synchronized
Input
Hysteresis
Discrete
I/O
Port
Designation
PCS0/SS
Bo
Yes2
Yes
I/O
PQS3
PCS[3:1]
Bo
Yes2
Yes
I/O
PQS[6:4]
RESET
Bo
Yes
Yes
—
—
RMC
A
Yes
Yes
I/O
PE3
R/W
A
Yes
No
—
—
RXD
—
No
Yes
—
—
SCK
Bo
Yes2
Yes
I/O
PQS2
SIZ[1:0]
B
Yes
No
I/O
PE[7:6]
TSC
—
Yes
Yes
—
—
TXD
Bo
2
Yes
Yes
I/O
PQS7
XFC
—
—
—
—
—
XRTC
—
—
—
—
—
XTAL
—
—
—
—
—
NOTES:
1. HALT and BERR synchronized only if late HALT or BERR.
2. DATA[15:0] synchronized during reset only. MODCLK and QSM pins synchronized only if used as port I/O pins.
2.2 MCU Power Connections
Table 3 MCU Power Connections
VDDSYN
Clock Synthesizer
VDDE, VSSE
External periphery power (source and drain)
VDDI, VSSI
Internal module power (source and drain)
VRTC
RTCSM/RAMSM standby power
VSSRTCOSC
Ground connection for real-time clock oscillator
2.3 MCU Driver Types
Table 4 MCU Output Driver Types
Type
A
Output-only signals that are always driven; no external pull-up required
Ao
Type A output that can be operated in an open drain mode
Aw
Type A output with weak P-channel pull-up during reset
B
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Description
Three-state output that includes circuitry to pull up output before high impedance
is established, to ensure rapid rise time. An external holding resistor is required to
maintain logic level while the pin is in the high-impedance state.
Bw
Type B output with weak P-channel pull-up during reset
Bo
Type B output that can be operated in an open-drain mode
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2.4 Signal Characteristics
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Table 5 MCU Signal Characteristics
Signal Name
MCU Module
Signal Type
Active State
ADDR[23:0]
SIML
Bus
—
AS
SIML
Output
0
AVEC
SIML
Input
0
BERR
SIML
Input
0
BG
SIML
Output
0
BGACK
SIML
Input
0
BKPT
CPU32L
Input
0
BR
SIML
Input
0
CLKOUT
SIML
Output
—
CS[10:0]
SIML
Output
0
CSBOOT
SIML
Output
0
CTD[29:26]
CTM6
Input/Output
—
CTD[10:4]
CTM6
Input/Output
—
CTIO[5:0]
CTM6
Input/Output
—
CTM31L
CTM6
Input
—
CTS24[B:A]
CTM6
Input/Output
—
CTS18[B:A]
CTM6
Input/Output
—
CTS14[B:A]
CTM6
Input/Output
—
DATA[15:0]
SIML
Bus
—
DS
SIML
Output
0
DSACK[1:0]
SIML
Input
0
DSCLK
CPU32L
Input
Serial Clock
DSI
CPU32L
Input
—
DSO
CPU32L
Output
—
EXRTC
CTM6
Input
—
EXTAL
SIML
Input
—
FC[2:0]
SIML
Output
—
FREEZE
SIML
Output
1
HALT
SIML
Input/Output
0
IFETCH
CPU32L
Output
—
IPIPE
CPU32L
Output
—
IRQ[7:1]
SIML
Input
0
MISO
QSM
Input/Output
—
MODCLK
SIML
Input
—
MOSI
QSM
Input/Output
—
PC[6:0]
SIML
Output
—
PCS[3:0]
QSM
Input/Output
—
PE[7:0]
SIML
Input/Output
—
PF[7:0]
SIML
Input/Output
—
PQS[7:0]
QSM
Input/Output
—
QUOT
SIML
Output
—
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Table 5 MCU Signal Characteristics (Continued)
Signal Name
MCU Module
Signal Type
Active State
RESET
SIML
Input/Output
0
RMC
SIML
Output
0
R/W
SIML
Output
0
RXD
QSM
Input
—
SCK
QSM
Input/Output
—
SIZ[1:0]
SIML
Output
—
SS
QSM
Input
0
TSC
SIML
Input
—
TXD
QSM
Output
—
XFC
SIML
Input
—
XRTC
CTM6
Output
—
XTAL
SIML
Output
—
2.5 Signal Function
Table 6 MCU Signal Function
Signal Name
Mnemonic
Address Bus
ADDR[23:0]
Address Strobe
AS
Function
24-bit address bus
Indicates that a valid address is on the address bus
Autovector
AVEC
Requests an automatic vector during interrupt acknowledge
Bus Error
BERR
Signals a bus error to the CPU
Bus Grant
BG
Bus Grant
Acknowledge
BGACK
Breakpoint
BKPT
Bus Request
BR
System Clockout
CLKOUT
System clock output
Indicates that the MCU has relinquished the bus
Indicates that an external device has assumed bus mastership
Signals a hardware breakpoint to the CPU
Indicates that an external device requires bus mastership
Chip Selects
CS[10:0]
Select external devices at programmed addresses
Boot Chip Select
CSBOOT
Chip select for external boot startup ROM
Configurable Timer
Double-Action
CTD[29:26],
CTD[10:4]
Configurable Timer
Modulus Counter
Load
CTM31L
RTC Configurable
Timer Oscillator
EXRTC, XRTC
Configurable Timer
Port Input/Output
CTIO[5:0]
Configurable Timer
Single-Action
CTS24[B:A]
CTS18[B:A]
CTS14[B:A]
Crystal Oscillator
EXTAL, XTAL
Data Bus
DATA[15:0]
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Double-action submodule (DASM) signals.
Can also be used as general purpose I/O pins
External load for modulus counter.
Can also be used as general purpose input
CTM real time clock oscillator input/output
General-purpose I/O pins
Single-action submodule (SASM) signals.
Can also be used as general purpose I/O pins
Connections for clock synthesizer circuit reference; a crystal or an
external oscillator can be used
16-bit data bus
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Table 6 MCU Signal Function (Continued)
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Signal Name
Mnemonic
Function
Data Strobe
DS
Indicates that an external device should place valid data on the data bus
during a read cycle and that valid data has been placed on the bus by
the CPU during a write cycle
Data and Size
Acknowledge
DSACK[1:0]
Acknowledges to the SIML that data has been received for a write cycle,
or that data is valid on the data bus for a read cycle
Development Serial
In, Out, Clock
DSI, DSO,
DSCLK
Function Codes
FC[2:0]
Freeze
FREEZE
Halt
HALT
Instruction Pipeline
IFETCH, IPIPE
Interrupt Request
Level
IRQ[7:1]
Master In Slave Out
MISO
Clock Mode Select
MODCLK
Serial I/O and clock for background debugging mode
Identify processor state and current address space
Indicates that the CPU has entered background mode
Suspend external bus activity
Indicate instruction pipeline activity
Request interrupt service from the CPU
Serial input to QSPI in master mode;
serial output from QSPI in slave mode
Selects system clock source
Serial output from QSPI in master mode;
serial input to QSPI in slave mode
Master Out Slave In
MOSI
Port C
PC[6:0]
Peripheral Chip
Select
PCS[3:0]
Port E
PE[7:0]
SIML digital input or output port signals
Port F
PF[7:0]
SIML digital input or output port signals
SIML digital output signals
QSPI peripheral chip selects
Port QS
PQS[7:0]
Quotient Out
QUOT
QSM digital I/O port signals
Provides the quotient bit of the polynomial divider
Reset
RESET
System reset
Read-Modify-Write
Cycle
RMC
Read/Write
R/W
Indicates the direction of data transfer on the bus
SCI Receive Data
RXD
Serial input to the SCI
QSPI Serial Clock
SCK
Clock output from QSPI in master mode;
clock input to QSPI in slave mode
Size
SIZ[1:0]
Slave Select
SS
Indicates an indivisible read-modify-write instruction
Indicates the number of bytes to be transferred during a bus cycle
Causes serial transmission when QSPI is in slave mode.
Causes mode fault in master mode
Three-State Control
TSC
Places all output drivers in a high-impedance state
SCI Transmit Data
TXD
Serial output from the SCI
External Filter
Capacitor
XFC
MC68CK338
MC68CK338TS/D
Connection for external phase-locked loop filter capacitor
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3 Low-Power System Integration Module
The low-power system integration module (SIML) consists of five functional blocks that control system
startup, initialization, configuration, and the external bus. Figure 4 shows the SIML block diagram.
SYSTEM CONFIGURATION
CLOCK SYNTHESIZER
XTAL
CLKOUT
EXTAL
MODCLK
Freescale Semiconductor, Inc...
SYSTEM PROTECTION
CHIP-SELECTS
CHIP-SELECTS
EXTERNAL BUS
EXTERNAL BUS INTERFACE
RESET
FACTORY TEST
TSC
FREEZE/QUOT
338 S(C)IM BLOCK
Figure 4 SIML Block Diagram
3.1 Overview
The system configuration block controls MCU configuration and operating mode.
The clock synthesizer generates clock signals used by the SIML, other IMB modules, and external devices. In addition, a periodic interrupt generator supports execution of time-critical control routines.
The system protection block provides bus and software watchdog monitors.
The chip-select block provides eleven general-purpose chip-select signals and a boot ROM chip-select
signal. Both general-purpose and boot ROM chip-select signals have associated base address registers and option registers.
The external bus interface handles the transfer of information between IMB modules and external address space.
The system test block incorporates hardware necessary for testing the MCU. It is used to perform factory tests, and its use in normal applications is not supported.
Table 7 shows the SIML address map, which occupies 128 bytes. Unused registers within the 128-byte
address space return zeros when read. The “Access” column indicates which registers are accessible
only at the supervisor privilege level and which can be assigned to either the supervisor or user privilege
level, according to the value of the SUPV bit in the SIMLCR.
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Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc...
Table 7 SIML Address Map
Access
Address1
S
$YFFA00
S
$YFFA02
SIML Test Register (SIMLTR)
S
$YFFA04
Clock Synthesizer Control Register (SYNCR)
S
$YFFA06
S
$YFFA08
15
8 7
0
SIML Module Configuration Register (SIMLCR)
Not Used
Reset Status Register (RSR)
SIML Test Register E (SIMLTRE)
—
$YFFA0A
Not Used
—
$YFFA0C
Not Used
—
$YFFA0E
Not Used
S/U
$YFFA10
Not Used
S/U
$YFFA12
Not Used
Port E Data (PORTE1)
S/U
$YFFA14
Not Used
Port E Data Direction (DDRE)
S
$YFFA16
Not Used
Port E Pin Assignment (PEPAR)
S/U
$YFFA18
Not Used
Port F Data (PORTF0)
S/U
$YFFA1A
Not Used
Port F Data (PORTF1)
S/U
$YFFA1C
Not Used
Port F Data Direction (DDRF)
S
$YFFA1E
Not Used
Port F Pin Assignment (PFPAR)
S
$YFFA20
Not Used
System Protection Control (SYPCR)
S
$YFFA22
Periodic Interrupt Control Register (PICR)
S
$YFFA24
Periodic Interrupt Timer Register (PITR)
S
$YFFA26
S
$YFFA28
Not Used
S
$YFFA2A
Not Used
S
$YFFA2C
Not Used
S
$YFFA2E
Not Used
S
$YFFA30
Test Module Master Shift A (TSTMSRA)
S
$YFFA32
Test Module Master Shift B (TSTMSRB)
S
$YFFA34
Test Module Shift Count (TSTSC)
S
$YFFA36
Test Module Repetition Counter (TSTRC)
S
$YFFA38
Test Module Control (CREG)
S/U
$YFFA3A
Test Module Distributed Register (DREG)
—
$YFFA3C
Not Used
—
$YFFA3E
Not Used
S/U
$YFFA40
—
$YFFA42
Not Used
S
$YFFA44
Chip-Select Pin Assignment (CSPAR0)
S
$YFFA46
Chip-Select Pin Assignment (CSPAR1)
S
$YFFA48
Chip-Select Base Boot (CSBARBT)
S
$YFFA4A
Chip-Select Option Boot (CSORBT)
S
$YFFA4C
Chip-Select Base 0 (CSBAR0)
S
$YFFA4E
Chip-Select Option 0 (CSOR0)
S
$YFFA50
Chip-Select Base 1 (CSBAR1)
MC68CK338
MC68CK338TS/D
Port E Data (PORTE0)
Not Used
Software Service (SWSR)
Not Used
Port C Data (PORTC)
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Table 7 SIML Address Map (Continued)
Access
Address1
S
$YFFA52
Chip-Select Option 1 (CSOR1)
S
$YFFA54
Chip-Select Base 2 (CSBAR2)
S
$YFFA56
Chip-Select Option 2 (CSOR2)
15
8 7
0
S
$YFFA58
Chip-Select Base 3 (CSBAR3)
S
$YFFA5A
Chip-Select Option 3 (CSOR3)
S
$YFFA5C
Chip-Select Base 4 (CSBAR4)
S
$YFFA5E
Chip-Select Option 4 (CSOR4)
S
$YFFA60
Chip-Select Base 5 (CSBAR5)
S
$YFFA62
Chip-Select Option 5 (CSOR5)
S
$YFFA64
Chip-Select Base 6 (CSBAR6)
S
$YFFA66
Chip-Select Option 6 (CSOR6)
S
$YFFA68
Chip-Select Base 7 (CSBAR7)
S
$YFFA6A
Chip-Select Option 7 (CSOR7)
S
$YFFA6C
Chip-Select Base 8 (CSBAR8)
S
$YFFA6E
Chip-Select Option 8 (CSOR8)
S
$YFFA70
Chip-Select Base 9 (CSBAR9)
S
$YFFA72
Chip-Select Option 9 (CSOR9)
S
$YFFA74
Chip-Select Base 10 (CSBAR10)
S
$YFFA76
Chip-Select Option 10 (CSOR10)
—
$YFFA78
Not Used
—
$YFFA7A
Not Used
—
$YFFA7C
Not Used
—
$YFFA7E
Not Used
NOTES:
1. Y = M111, where M is the logic state of the module mapping (MM) bit in the SIMLCR.
3.2 System Configuration Block
This functional block provides configuration control for the entire MCU. It also performs interrupt arbitration, bus monitoring, and system test functions.
3.2.1 MCU Configuration
The SIML controls MCU configuration during normal operation and during internal testing.
SIMLCR — SIML Configuration Register
15
14
13
EXOFF FRZSW FRZBM
12
11
10
0
SLVEN
0
0
DATA11
0
$YFFA00
9
8
SHEN
7
6
5
4
SUPV
MM
0
0
1
1
0
0
3
2
1
0
IARB[3:0]
RESET:
0
0
0
0
0
1
1
1
1
The SIML configuration register controls system configuration. It can be read or written at any time, except for the module mapping (MM) bit, which can be written only once.
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EXOFF — External Clock Off
0 = The CLKOUT pin is driven by the MCU system clock.
1 = The CLKOUT pin is placed in a high-impedance state.
FRZSW — Freeze Software Enable
0 = When FREEZE is asserted, the software watchdog and periodic interrupt timer counters continue to run.
1 = When FREEZE is asserted, the software watchdog and periodic interrupt timer counters are disabled, preventing interrupts while the MCU is in background debug mode.
Freescale Semiconductor, Inc...
FRZBM — Freeze Bus Monitor Enable
0 = When FREEZE is asserted, the bus monitor continues to operate.
1 = When FREEZE is asserted, the bus monitor is disabled.
SLVEN — Factory Test Mode Enabled
This bit is a read-only status bit that reflects the state of DATA11 during reset.
0 = IMB is not available to an external master.
1 = An external bus master has direct access to the IMB.
SHEN[1:0] — Show Cycle Enable
This field determines what the EBI does with the external bus during internal transfer operations. A
show cycle allows internal transfers to be externally monitored. Table 8 shows whether show cycle data
is driven externally, and whether external bus arbitration can occur. To prevent bus conflict, external
peripherals must not be enabled during show cycles.
Table 8 Show Cycle Enable Bits
SHEN
Action
00
Show cycles disabled, external bus arbitration allowed
01
Show cycles enabled, external bus arbitration not allowed
10
Show cycles enabled, external bus arbitration allowed
11
Show cycles enabled, external bus arbitration allowed,
internal activity is halted by a bus grant
SUPV — Supervisor/Unrestricted Data Space
The SUPV bit places the SIML global registers in either supervisor or user data space.
0 = Registers with access controlled by the SUPV bit are accessible in either supervisor or user
data space.
1 = Registers with access controlled by the SUPV bit are accessible in supervisor data space only.
MM — Module Mapping
0 = Internal modules are addressed from $7FF000 – $7FFFFF.
1 = Internal modules are addressed from $FFF000 – $FFFFFF.
IARB[3:0] — Interrupt Arbitration Field
Each module that can generate interrupt requests has an interrupt arbitration (IARB) field. Arbitration
between interrupt requests of the same priority is performed by serial contention between IARB field bit
values. Contention must take place whenever an interrupt request is acknowledged, even when there
is only a single pending request. An IARB field must have a non-zero value for contention to take place.
If an interrupt request from a module with an IARB field value of %0000 is recognized, the CPU processes a spurious interrupt exception. Because the SIML routes external interrupt requests to the CPU,
the SIML IARB field value is used for arbitration between internal and external interrupts of the same
priority. The reset value of IARB for the SIML is %1111, and the reset value of IARB for all other modules is %0000, which prevents SIML interrupts from being discarded during initialization.
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3.3 System Clock
The system clock in the SIML provides timing signals for the IMB modules and for an external peripheral
bus. Because the MCU is a fully static design, register and memory contents are not affected when the
clock rate changes. System hardware and software support changes in clock rate during operation.
The system clock signal can be generated in one of two ways. An internal phase-locked loop can
synthesize the clock from a reference frequency, or the clock signal can be input directly from an
external source. Keep these clock sources in mind while reading the rest of this section. Figure 5 is a
block diagram of the system clock.
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MODCLK
EXTAL
XTAL
CRYSTAL
OSCILLATOR
PHASE
COMPARATOR
XFC
VDDSYN
LOW-PASS
FILTER
VCO
FEEDBACK DIVIDER
SYSTEM CLOCK CONTROL
CLKOUT
W
Y
X
SYSTEM
CLOCK
16/32 PLL BLOCK
Figure 5 System Clock Block Diagram
3.3.1 Clock Sources
The state of the clock mode (MODCLK) pin during reset determines the system clock source. When
MODCLK is held high during reset, the clock synthesizer generates a clock signal from a reference
frequency connected to the EXTAL pin. The clock synthesizer control register (SYNCR) determines
operating frequency and mode of operation. When MODCLK is held low during reset, the clock
synthesizer is disabled and an external system clock signal must be applied. The SYNCR control bits
have no effect.
The input clock is referred to as “fref”, and can be either a crystal or an external clock source. The output
of the clock system is referred to as “fsys”. Ensure that fref and fsys are within normal operating limits.
The reference frequency for this MCU is typically 32.768 kHz, but can range from 25 kHz to 50 kHz. To
generate a reference frequency using the crystal oscillator, a reference crystal must be connected between the EXTAL and XTAL pins. Figure 6 shows a recommended circuit.
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MC68CK338TS/D
Freescale Semiconductor, Inc.
C1
22 pF*
R1
4.7 kΩ*
XTAL
R2
10MΩ*
EXTAL
C2
22 pF*
VSSI
* RESISTANCE AND CAPACITANCE BASED ON A TEST CIRCUIT CONSTRUCTED WITH A DAISHINKU DMX-38 32.768 kHZ CRYSTAL.
SPECIFIC COMPONENTS MUST BE BASED ON CRYSTAL TYPE. CONTACT CRYSTAL VENDOR FOR EXACT CIRCUIT.
338 OSCILLATOR
Freescale Semiconductor, Inc...
Figure 6 System Clock Oscillator Circuit
When an external system clock signal is applied (PLL disabled, MODCLK = 0 during reset), the duty
cycle of the input is critical, especially at operating frequencies close to maximum. The relationship between clock signal duty cycle and clock signal period is expressed:
Minimum External Clock High/Low Time
Minimum External Clock Period = -----------------------------------------------------------------------------------------------------------------------------------------------------------------------50 % – Percentage Variation of External Clock Input Duty Cycle
When the system clock signal is applied directly to the EXTAL pin (PLL is disabled, MODCLK = 0 during
reset), or the clock synthesizer reference frequency is supplied by a source other than a crystal (PLL
enabled, MODCLK = 1 during reset), the XTAL pin must be left floating. In either case, the frequency of
the signal applied to EXTAL may not exceed the maximum system clock frequency (PLL disabled) or
the maximum clock synthesizer reference frequency (PLL enabled).
3.3.2 Clock Synthesizer Operation
VDDSYN is used to power the clock circuits when the phase-locked loop is used. A separate power
source increases MCU noise immunity and can be used to run the clock when the MCU is powered
down. A quiet power supply must be used as the VDDSYN source. Adequate external bypass capacitors
should be placed as close as possible to the VDDSYN pin to assure stable operating frequency. When
an external system clock signal is applied and the PLL is disabled, VDDSYN should be connected to the
VDD supply. Refer to the SIM Reference Manual (SIMRM/AD) for more information regarding system
clock power supply conditioning.
A voltage controlled oscillator (VCO) generates the system clock signal. To maintain a 50% clock duty
cycle, the VCO frequency (fVCO) is either two or four times the system clock frequency, depending on
the state of the X bit in SYNCR. A portion of the clock signal is fed back to a divider/counter. The divider
controls the frequency of one input to a phase comparator. The other phase comparator input is the
reference signal connected to the EXTAL pin. The comparator generates a control signal proportional
to the difference in phase between the two inputs. The signal is low-pass filtered and used to correct
the VCO output frequency.
Filter circuit implementation can vary, depending upon the external environment and required clock stability. Figure 7 shows a recommended system clock filter network. XFC pin leakage must be kept within
specified limits to maintain optimum stability and PLL performance.
An external filter network connected to the XFC pin is not required when an external system clock signal
is applied and the PLL is disabled. The XFC pin must be left floating in this case.
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C3
0.1µF
VDDSYN
C1
0.1µF
XFC *
VDDSYN
C4
0.01µF
VSSI
* MAINTAIN LOW LEAKAGE ON THE XFC NODE.
32 XFC CONN
Freescale Semiconductor, Inc...
Figure 7 System Clock Filter Network
When the clock synthesizer is used, SYNCR determines the operating frequency of the MCU. The following equation relates the MCU operating frequency to the clock synthesizer reference frequency (fref)
and the W, X, and Y fields in the SYNCR:
f sys = 4f ref ( Y + 1 ) ( 2
2W + X
)
The W bit controls a prescaler tap in the feedback divider. Setting W increases VCO speed by a factor
of four. The Y field determines the count modulus for a modulo 64 downcounter, causing it to divide by
a value of Y+1. When W or Y changes, VCO frequency (fVCO) changes, and the VCO must relock.
The X bit controls a divide-by-two circuit that is not in the synthesizer feedback loop. When X=0 (reset
state), the divider is enabled, and the system clock is one-fourth the VCO frequency. Setting X=1
disables the divider, doubling the clock speed without changing the VCO frequency. There is no relock
delay when clock speed is changed by the X bit.
Internal VCO frequency is determined by the following equations:
f VCO = 4f sys if X = 0
or
f VCO = 2f sys if X = 1
For the MCU to operate correctly, system clock and VCO frequencies selected by the W, X, and Y bits
must be within the limits specified for the MCU. Do not use a combination of bit values that selects either
an operating frequency or a VCO frequency greater than the maximum specified values.
3.3.3 Clock Synthesizer Control
The clock synthesizer control circuits determine system clock frequency and clock operation under special circumstances, such as following loss of synthesizer reference or during low-power operation. Clock
source is determined by the logic state of the MODCLK pin during reset.
SYNCR — Clock Synthesizer Control Register
15
14
W
13
12
11
X
10
9
$YFFA04
8
Y
7
6
5
4
EDIV
STCPU
0
RSVD1
0
0
0
0
3
2
SLOCK RSVD1
1
0
STSIM
STEXT
0
0
RESET:
0
0
1
1
1
1
1
1
U
0
NOTES:
1. Ensure that initialization software does not change the value of this bit (it should always be zero).
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When the on-chip clock synthesizer is used, system clock frequency is controlled by the bits in the upper
byte of SYNCR. Bits in the lower byte show the status of or control the operation of internal and external
clocks. SYNCR can be read or written only when the CPU is operating in supervisor mode.
W — Frequency Control (VCO)
This bit controls a prescaler tap in the synthesizer feedback loop. Setting it increases the VCO speed
by a factor of four. VCO relock delay is required.
X — Frequency Control (Prescaler)
This bit controls a divide by two prescaler that is not in the synthesizer feedback loop. Setting it doubles
the clock speed without changing the VCO speed. No VCO relock delay is required.
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Y[5:0] — Frequency Control (Counter)
The Y field controls the modulus down counter in the synthesizer feedback loop, causing it to divide by
a value of Y + 1. Values range from 0 to 63. VCO relock delay is required.
EDIV — E Clock Divide Rate
0 = ECLK frequency is system clock divided by 8.
1 = ECLK frequency is system clock divided by 16.
ECLK is an external M6800 bus clock available on pin ADDR23. Refer to 3.6 Chip-Selects for more
information.
STCPU — Stop CPU32L Clock on LPSTOP
0 = When LPSTOP is executed, the intermodule bus clock (IMBCLK) is held low. When a trace,
reset exception, or SIML interrupt occurs, the IMBCLK turns back on and the CPU32L begins
executing instructions again.
1 = When LPSTOP is executed, the IMBCLK continues to run but is gated off and held low only
where it enters the CPU32L. When a trace, reset exception, or interrupt from any module occurs, the IMBCLK is gated back on where it enters the CPU32L, and execution begins again.
SLOCK — Synthesizer Lock Flag
0 = VCO has not locked, but is enabled on the desired frequency.
1 = VCO has locked on the desired frequency, or is disabled.
The MCU remains in reset until the synthesizer locks, but SLOCK does not indicate synthesizer lock
status until after the user writes to SYNCR.
STSIM — Stop Mode SIML Clock
0 = When LPSTOP is executed, the SIML clock is driven by the crystal oscillator and the VCO is
turned off to conserve power.
1 = When LPSTOP is executed, the SIML clock is driven by the VCO.
STEXT — Stop Mode External Clock
0 = When LPSTOP is executed, the CLKOUT signal is held negated to conserve power.
1 = When LPSTOP is executed, the CLKOUT signal is driven by the SIML clock, as determined by
the state of the STSIM bit.
3.3.4 External MC6800 Bus Clock
The state of the ECLK division rate bit (EDIV) in SYNCR determines clock rate for the ECLK signal available on pin ADDR23. ECLK is a bus clock for MC6800 devices and peripherals. ECLK frequency can
be set to system clock frequency divided by eight or system clock frequency divided by sixteen. The
clock is enabled by the CS10 field in chip-select pin assignment register 1 (CSPAR1). ECLK operation
during low-power stop is described in the following paragraph. Refer to 3.6 Chip-Selects for more information about the external bus clock.
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3.3.5 Low-Power Operation
Low-power operation is initiated by the CPU32L. To reduce power consumption selectively, the
CPU32L can enter the following low-power modes:
1. The CPU32L can selectively disable a module by setting the module’s STOP bit.
2. The CPU32L can execute the STOP instruction.
3. The CPU32L can execute the LPSTOP instruction to stop the operations of only the CPU32L
or the entire MCU, including the CPU32L.
If the STOP bit in a module is set, then that module enters a low power mode. Some or all of that module’s registers remain accessible. The module can be restarted by asserting RESET or by the CPU32L
clearing the module’s STOP bit.
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The CPU32L can enter a low power mode by executing the STOP instruction. It can be reawakened by
RESET, trace or interrupt.
3.3.5.1 Normal LPSTOP mode
This low-power stop mode offers the greatest power reduction. To enter normal LPSTOP mode, the
CPU32L executes the LPSTOP instruction after clearing the STCPU bit in SYNCR. This causes the
SIML to turn off the system clock to most of the MCU.
When the CPU executes LPSTOP, a special CPU space bus cycle writes a copy of the current interrupt
mask into the clock control logic. The SIML brings the MCU out of normal LPSTOP mode when one of
the following exceptions occurs:
• RESET
• Trace
• SIML interrupt of higher priority than the stored interrupt mask
During a LPSTOP, unless the system clock signal is supplied by an external source and that source is
removed, the SIML clock control logic and the SIML clock signal (SIMCLK) continue to operate. The
periodic interrupt timer and input logic for the RESET and IRQ pins are clocked by SIMCLK, and can
be used to bring the processor out of LPSTOP. The software watchdog monitor cannot perform this
function. Optionally, the SIML can also continue to generate the CLKOUT signal while in LPSTOP.
STSIM and STEXT bits in SYNCR determine clock operation during LPSTOP.
3.3.5.2 Modified LPSTOP mode
To enter modified LPSTOP mode, the CPU32L first sets the STCPU bit in SYNCR, then executes the
LPSTOP instruction. This causes the SIML to turn off the system clock to the CPU32L only. The other
MCU modules continue to operate. The SIML brings the MCU out of normal LPSTOP mode when one
of the following exceptions occurs:
• RESET
• Trace
• Interrupt of higher priority than the stored interrupt mask from any MCU module
This low-power stop mode offers better power reduction than using the STOP instruction since the clock
in the CPU32L is held inactive. Also, the STOP bits of individual modules may be set or cleared, leaving
some active and others inactive. The flow chart shown in Figure 8 summarizes the effects of the
STCPU, STSIM, and STEXT bits when the MCU enters normal or modified LPSTOP mode.
NOTE
To keep power consumption to a minimum when in LPSTOP mode, do not allow
any spurious interrupts to occur. If a spurious interrupt occurs during LPSTOP
mode, the device will transition to the STOP mode (which has greater power
consumption) until a non-spurious interrupt request is detected by the CPU32L.
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SETUP INTERRUPT
TO WAKE UP MCU
FROM LPSTOP
LEAVE IMBCLK1
ON IN LPSTOP?
NO
YES
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SET STOP BITS FOR
MODULES THAT WILL
NOT BE ACTIVE IN
LPSTOP
SET STCPU2 = 1
fimbclk = fsys
IN LPSTOP
USING
EXTERNAL CLOCK?
SET STCPU2 = 0
fimbclk = 0 Hz
IN LPSTOP
NO
YES
USE SYSTEM CLOCK
AS SIMCLK IN LPSTOP?
NO
YES
SET STSIM = 1
fsimclk3 = fsys
IN LPSTOP
WANT CLKOUT
ON IN LPSTOP?
NO
WANT CLKOUT
ON IN LPSTOP?
YES
SET STEXT = 1
fclkout4 = fsys
feclk = ÷ fsys
IN LPSTOP
SET STSIM = 0
fsimclk3 = fref
IN LPSTOP
NO
YES
SET STEXT = 0
fclkout4 = 0 Hz
feclk = ÷ 0 Hz
IN LPSTOP
SET STEXT = 1
fclkout4 = fref
feclk = ÷ 0 Hz
IN LPSTOP
SET STEXT = 0
fclkout4 = 0 Hz
feclk = ÷ 0 Hz
IN LPSTOP
ENTER LPSTOP
NOTES:
1. IMBCLK IS THE CLOCK USED BY THE CPU32L, QSM, CTM6, AND THE SIML.
2. WHEN STCPU = 1, THE CPU32L IS SHUTDOWN IN LPSTOP. ALL OTHER MODULES WILL REMAIN ACTIVE UNLESS
THE STOP BITS IN THEIR MODULE CONFIGURATION REGISTERS ARE SET PRIOR TO ENTERING LPSTOP.
3. THE SIMCLK IS USED BY THE PIT, IRQ, AND INPUT BLOCKS OF THE SIML.
4. CLKOUT CONTROL DURING LPSTOP IS OVERRIDDEN BY THE EXOFF BIT IN SIMLCR. IF EXOFF = 1, THE CLKOUT
PIN IS ALWAYS IN A HIGH IMPEDANCE STATE AND STEXT HAS NO EFFECT IN LPSTOP. IF EXOFF = 0, CLKOUT
IS CONTROLLED BY STEXT IN LPSTOP. WHEN STCPU = 1, THE CPU32L IS DISABLED IN LPSTOP, BUT ALL OTHER
MODULES REMAIN ACTIVE OR STOPPED ACCORDING TO THE SETTING.
LPSTOP FLOWCHART
Figure 8 LPSTOP Flowchart
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3.4 System Protection Block
System protection includes a bus monitor, a halt monitor, a spurious interrupt monitor, and a software
watchdog timer. These functions reduce the number of external components required for complete system control. Figure 9 shows the system protection block.
MODULE CONFIGURATION
AND TEST
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RESET STATUS
HALT MONITOR
RESET REQUEST
BUS MONITOR
BERR
SPURIOUS INTERRUPT MONITOR
SOFTWARE WATCHDOG TIMER
CLOCK
RESET REQUEST
PRESCALER
29
PERIODIC INTERRUPT TIMER
IRQ[7:1]
SYS PROTECT BLOCK
Figure 9 System Protection Block
3.4.1 System Protection Control Register
The system protection control register controls the software watchdog timer, bus monitor, and halt
monitor. This register can be written only once following power-on or reset, but can be read at any time.
SYPCR — System Protection Control Register
15
14
13
12
11
10
NOT USED
9
$YFFA21
8
7
6
SWE
SWP
1
MODCLK
5
4
SWT[1:0]
3
2
HME
BME
0
0
1
0
BMT
RESET:
0
0
0
0
SWE — Software Watchdog Enable
0 = Software watchdog disabled
1 = Software watchdog enabled
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SWP — Software Watchdog Prescaler
This bit controls the value of the software watchdog prescaler.
0 = Software watchdog clock not prescaled
1 = Software watchdog clock prescaled by 512
SWT[1:0] — Software Watchdog Timing
This field selects the divide ratio used to establish software watchdog time-out period. Table 9 gives the
ratio for each combination of SWP and SWT bits.
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Table 9 Software Watchdog Timing Field
SWP
SWT[1:0]
Watchdog Time-Out Period
0
00
29 ÷ fsys
0
01
211 ÷ fsys
0
10
213 ÷ fsys
0
11
215 ÷ fsys
1
00
218 ÷ fsys
1
01
220 ÷ fsys
1
10
222 ÷ fsys
1
11
224 ÷ fsys
HME — Halt Monitor Enable
0 = Disable halt monitor function
1 = Enable halt monitor function
BME — Bus Monitor Enable
0 = Disable bus monitor function for internal to external bus cycles.
1 = Enable bus monitor function for internal to external bus cycles.
BMT[1:0] — Bus Monitor Timing
This bit field selects the time-out period in system clocks for the bus monitor. Refer to Table 10.
Table 10 Bus Monitor Time-Out Period
BMT[1:0]
Bus Monitor Time-Out Period
00
64 system clocks
01
32 system clocks
10
16 system clocks
11
8 system clocks
3.4.2 Bus Monitor
The internal bus monitor checks for excessively long DSACK response times during normal bus cycles
and for excessively long DSACK or AVEC response times during interrupt acknowledge (IACK) cycles.
The monitor asserts BERR if the response time exceeds a user-specified time-out period.
DSACK and AVEC response times are measured in clock cycles. The maximum allowable response
time can be selected by setting the BMT[1:0] field.
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The monitor does not check DSACK response on the external bus unless the CPU initiates the bus cycle. The BME bit in SYPCR enables the internal bus monitor for internal to external bus cycles. If a system contains external bus masters, an external bus monitor must be implemented and the internal to
external bus monitor option must be disabled.
3.4.3 Halt Monitor
The halt monitor responds to assertion of the HALT signal on the internal bus caused by a double bus
fault. A double bus fault occurs when:
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• Bus error exception processing begins and a second BERR is detected before the first instruction
of the first exception handler is executed.
• One or more bus errors occur before the first instruction after a reset exception is executed.
• A bus error occurs while the CPU is loading information from a bus error stack frame during a return from exception (RTE) instruction.
If the halt monitor is enabled by setting HME in SYPCR, the MCU will issue a reset when a double bus
fault occurs, otherwise the MCU will remain halted.
A flag in the reset status register (RSR) indicates that the last reset was caused by the halt monitor.
3.4.4 Spurious Interrupt Monitor
The spurious interrupt monitor issues BERR if no interrupt arbitration occurs during an interrupt acknowledge cycle. Leaving IARB[3:0] set to %0000 in the module configuration register of any peripheral
that can generate interrupts will cause a spurious interrupt.
3.4.5 Software Watchdog
The software watchdog is controlled by SWE in SYPCR. Once enabled, the watchdog requires that a
service sequence be written to SWSR on a periodic basis. If servicing does not take place, the watchdog
times out and issues a reset. This register can be written at any time, but returns zeros when read.
SWSR — Software Service Register
15
14
13
12
11
10
$YFFA27
9
8
7
6
5
4
NOT USED
3
2
1
0
0
0
0
0
SWSR
RESET:
0
0
0
0
Each time the service sequence is written, the software watchdog timer restarts. The servicing sequence consists of the following steps:
1. Write $55 to SWSR.
2. Write $AA to SWSR.
Both writes must occur before time-out in the order listed, but any number of instructions can be executed between the two writes.
The watchdog clock rate is affected by SWP and SWT[1:0] in SYPCR. When SWT[1:0] are modified, a
watchdog service sequence must be performed before the new time-out period takes effect.
The reset value of SWP is affected by the state of the MODCLK pin on the rising edge of RESET. Refer
to Table 11.
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Table 11 MODCLK Pin States
MODCLK
SWP
0
1
1
0
3.4.6 Periodic Interrupt Timer
The periodic interrupt timer (PIT) generates interrupts at user-programmable intervals. Timing for the
PIT is provided by a programmable prescaler driven by the system clock.
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PICR — Periodic Interrupt Control Register
15
14
13
12
11
0
0
0
0
0
0
0
0
0
10
9
$YFFA22
8
7
6
5
4
PIRQL[2:0]
3
2
1
0
1
1
1
1
PIV[7:0]
RESET:
0
0
0
0
0
0
0
0
This register contains information concerning periodic interrupt priority and vectoring. Bits [10:0] can be
read or written at any time. Bits [15:11] are unimplemented and always return zero.
PIRQL[2:0] — Periodic Interrupt Request Level
Table 12 shows what interrupt request level is asserted when a periodic interrupt is generated. If a PIT
interrupt and an external IRQ signal of the same priority occur simultaneously, the PIT interrupt is serviced first. The periodic timer continues to run when the interrupt is disabled.
Table 12 Periodic Interrupt Request Levels
PIRQL[2:0]
Interrupt Request Level
000
Periodic Interrupt Disabled
001
Interrupt Request Level 1
010
Interrupt Request Level 2
011
Interrupt Request Level 3
100
Interrupt Request Level 4
101
Interrupt Request Level 5
110
Interrupt Request Level 6
111
Interrupt Request Level 7
PIV[7:0] — Periodic Interrupt Vector
This bit field contains the vector generated in response to an interrupt from the periodic timer. When the
SIML responds, the periodic interrupt vector is placed on the bus.
PITR — Periodic Interrupt Timer Register
$YFFA24
15
14
13
12
11
10
9
8
0
0
0
0
0
0
0
PTP
0
0
0
0
0
0
MODCLK
7
6
5
4
3
2
1
0
0
0
0
PITM[7:0]
RESET:
0
0
0
0
0
0
PITR contains the count value for the periodic timer. Setting the PITM[7:0] field turns off the periodic
timer. This register can be read or written at any time.
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PTP — Periodic Timer Prescaler Control
0 = Periodic timer clock not prescaled
1 = Periodic timer clock prescaled by 512
The reset state of PTP is the complement of the state of the MODCLK signal at the rising edge of
RESET.
PITM[7:0] — Periodic Interrupt Timer Modulus
This is an 8-bit timing modulus. The period of the timer can be calculated as follows:
4 ( PITM[7:0] ) ( Prescaler )
PIT Period = ----------------------------------------------------------------f ref
where
PIT Period = Periodic interrupt timer period
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PITM[7:0] = Periodic interrupt timer register modulus
fref = Synthesizer reference of external clock input frequency
Prescaler = 1 if PTP = 0 or 512 if PTP = 1
3.5 External Bus Interface
The external bus interface (EBI) transfers information between the internal MCU bus and external devices. The external bus has 24 address lines and 16 data lines.
The EBI provides dynamic sizing between 8-bit and 16-bit data accesses. It supports byte, word, and
long-word transfers. Ports are accessed through the use of asynchronous cycles controlled by the size
(SIZ1 and SIZ0) and data size acknowledge (DSACK1 and DSACK0) pins. Multiple bus cycles may be
required for dynamically sized transfer.
Port width is the maximum number of bits accepted or provided during a bus transfer. External devices
must follow the handshake protocol described below. Control signals indicate the beginning of the cycle,
the address space, the size of the transfer, and the type of cycle. The selected device controls the length
of the cycle. Strobe signals, one for the address bus and another for the data bus, indicate the validity
of an address and provide timing information for data. The EBI operates in an asynchronous mode for
any port width.
To add flexibility and minimize the necessity for external logic, MCU chip-select logic can be synchronized with EBI transfers. Chip-select logic can also provide internally-generated bus control signals for
these accesses. Refer to 3.6 Chip-Selects for more information.
3.5.1 Bus Control Signals
The CPU initiates a bus cycle by driving the address, size, function code, and read/write outputs. At the
beginning of the cycle, size signals SIZ0 and SIZ1 are driven along with the function code signals
(FC[2:0]). The size signals indicate the number of bytes remaining to be transferred during an operand
cycle. They are valid while the address strobe AS is asserted.
Table 13 shows SIZ0 and SIZ1 encoding. The read/write (R/W) signal determines the direction of the
transfer during a bus cycle. This signal changes state, when required, at the beginning of a bus cycle,
and is valid while AS is asserted. The R/W signal only changes state when a write cycle is preceded by
a read cycle or vice versa. The signal can remain low for two consecutive write cycles.
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Table 13 Size Signal Encoding
SIZ1
SIZ0
Transfer Size
0
1
Byte
1
0
Word
1
1
Three Byte
0
0
Long Word
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3.5.2 Function Codes
The CPU32L automatically generates function code signals FC[2:0]. The function codes can be considered address extensions that automatically select one of eight address spaces to which an address applies. These spaces are designated as either user or supervisor, and program or data spaces. Address
space seven is designated CPU space. CPU space is used for control information not normally associated with read or write bus cycles. Function codes are valid while AS is asserted. Table 14 displays
CPU32L address space encodings.
Table 14 CPU32L Address Space Encoding
FC2
FC1
FC0
Address Space
0
0
0
Reserved
0
0
1
User Data Space
0
1
0
User Program Space
0
1
1
Reserved
1
0
0
Reserved
1
0
1
Supervisor Data Space
1
1
0
Supervisor Program Space
1
1
1
CPU Space
3.5.3 Address Bus
Address bus signals ADDR[23:0] define the address of the most significant byte to be transferred during
a bus cycle. The MCU places the address on the bus at the beginning of a bus cycle. The address is
valid while AS is asserted.
3.5.4 Address Strobe
AS is a timing signal that indicates the validity of an address on the address bus and the validity of many
control signals. It is asserted one-half clock after the beginning of a bus cycle.
3.5.5 Data Bus
Data bus signals DATA[15:0] make up a bidirectional, non-multiplexed parallel bus that transfers data
to or from the MCU. A read or write operation can transfer 8 or 16 bits of data in one bus cycle. During
a read cycle, the data is latched by the MCU on the last falling edge of the clock for that bus cycle. For
a write cycle, all 16 bits of the data bus are driven, regardless of the port width or operand size. The
MCU places the data on the data bus one-half clock cycle after AS is asserted in a write cycle.
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3.5.6 Data Strobe
Data strobe (DS) is a timing signal. For a read cycle, the MCU asserts DS to signal an external device
to place data on the bus. DS is asserted at the same time as AS during a read cycle. For a write cycle,
DS signals an external device that data on the bus is valid. The MCU asserts DS one full clock cycle
after the assertion of AS during a write cycle.
3.5.7 Bus Cycle Termination Signals
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During bus cycles, external devices assert the data size acknowledge signals DSACK1 and DSACK0.
During a read cycle, the signals tell the MCU to terminate the bus cycle and to latch data. During a write
cycle, the signals indicate that an external device has successfully stored data and that the cycle can
end. These signals also indicate to the MCU the size of the port for the bus cycle just completed. Alternately, chip-selects can be used to generate DSACK1 and DSACK0 internally. Refer to 3.5.8 Dynamic
Bus Sizing for more information.
The bus error (BERR) signal is also a bus cycle termination indicator and can be used in the absence
of DSACK1 and DSACK0 to indicate a bus error condition. It can also be asserted in conjunction with
these signals, provided it meets the appropriate timing requirements. The internal bus monitor can be
used to generate the BERR signal for internal-to-external transfers. When BERR and HALT are asserted simultaneously, the CPU takes a bus error exception.
The autovector signal (AVEC) can terminate IRQ pin interrupt acknowledge cycles. AVEC indicates that
the MCU will internally generate a vector number to locate an interrupt handler routine. If it is continuously asserted, autovectors will be generated for all external interrupt requests. AVEC is ignored during
all other bus cycles.
3.5.8 Dynamic Bus Sizing
The MCU dynamically interprets the port size of the addressed device during each bus cycle, allowing
operand transfers to or from 8- and 16-bit ports. During an operand transfer cycle, the slave device signals its port size and indicates completion of the bus cycle to the MCU through the use of the DSACK1
and DSACK0 inputs, as shown in Table 15.
Table 15 Effect of DSACK Signals
DSACK1
DSACK0
Result
1
1
Insert Wait States in Current Bus Cycle
1
0
Complete Cycle — Data Bus Port Size is 8 Bits
0
1
Complete Cycle — Data Bus Port Size is 16 Bits
0
0
Reserved
For example, if the MCU is executing an instruction that reads a long-word operand from a 16-bit port,
the MCU latches the 16 bits of valid data and then runs another bus cycle to obtain the other 16 bits.
The operation for an 8-bit port is similar, but requires four read cycles. The addressed device uses the
DSACK0 and DSACK1 signals to indicate the port width. For instance, a 16-bit device always returns
DSACK0 = 1 and DSACK1 = 0 for a 16-bit port, regardless of whether the bus cycle is a byte or word
operation.
Dynamic bus sizing requires that the portion of the data bus used for a transfer to or from a particular
port size be fixed. A 16-bit port must reside on data bus bits [15:0] and an 8-bit port must reside on data
bus bits [15:8]. This minimizes the number of bus cycles needed to transfer data and ensures that the
MCU transfers valid data.
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The MCU always attempts to transfer the maximum amount of data on all bus cycles. For a word operation, it is assumed that the port is 16 bits wide when the bus cycle begins. Operand bytes are designated as shown in Figure 10. OP0 is the most significant byte of a long-word operand, and OP3 is the
least significant byte. The two bytes of a word-length operand are OP0 (most significant) and OP1. The
single byte of a byte-length operand is OP0.
OPERAND
BYTE ORDER
31
LONG WORD
24 23
OP0
THREE BYTE
WORD
16 15
87
OP1
OP2
OP3
OP0
OP1
OP2
OP0
OP1
OP0
BYTE
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0
OPERAND BYTE ORDER
Figure 10 Operand Byte Order
3.5.9 Operand Alignment
The data multiplexer establishes the necessary connections for different combinations of address and
data sizes. The multiplexer takes the two bytes of the 16-bit bus and routes them to their required positions. Positioning of bytes is determined by the size and address outputs. SIZ1 and SIZ0 indicate the
remaining number of bytes to be transferred during the current bus cycle. The number of bytes transferred is equal to or less than the size indicated by SIZ1 and SIZ0, depending on port width.
ADDR0 also affects the operation of the data multiplexer. During an operand transfer, ADDR[23:1]
indicate the word base address of the portion of the operand to be accessed, and ADDR0 indicates the
byte offset from the base.
3.5.10 Misaligned Operands
CPU32L processor architecture uses a basic operand size of 16 bits. An operand is misaligned when it
overlaps a word boundary. This is determined by the value of ADDR0. When ADDR0 = 0 (an even address), the address is on a word and byte boundary. When ADDR0 = 1 (an odd address), the address
is on a byte boundary only.
A byte operand is aligned at any address; a word or long-word operand is misaligned at an odd address.
The CPU32L does not support misaligned operand transfers, and gives an address error exception if
one is attempted.
The largest amount of data that can be transferred by a single bus cycle is an aligned word. If the MCU
transfers a long-word operand via a 16-bit port, the most significant operand word is transferred on the
first bus cycle and the least significant operand word on a following bus cycle.
3.5.11 Operand Transfer Cases
Table 16 summarizes how operands are aligned for various types of transfers. OPn entries are portions
of a requested operand that are read or written during a bus cycle and are defined by SIZ1, SIZ0, and
ADDR0 for that bus cycle.
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Table 16 Operand Alignment
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Current
Cycle
Transfer Case1
SIZ1
SIZ0
ADDR0
DSACK1 DSACK0
DATA
[15:8]
DATA
[7:0]
Next
Cycle
1
Byte to 8-bit port (even)
0
1
0
1
0
OP0
(OP0)2
—
2
Byte to 8-bit port (odd)
0
1
1
1
0
OP0
(OP0)
—
3
Byte to 16-bit port (even)
0
1
0
0
1
OP0
(OP0)
—
4
Byte to 16-bit port (odd)
0
1
1
0
1
(OP0)
OP0
—
5
Word to 8-bit port
1
0
0
1
0
OP0
(OP1)
2
6
Word to 16-bit port
1
0
0
0
1
OP0
OP1
—
7
3-byte to 8-bit port3
1
1
1
1
0
OP0
(OP0)
5
8
Long word to 8-bit port
0
0
0
1
0
OP0
(OP0)
7
9
Long word to 16-bit port
0
0
0
0
1
OP0
OP1
6
NOTES:
1. All transfers are aligned. The CPU32L does not support misaligned word or long-word transfers.
2. Operands in parentheses are ignored by the CPU32L during read cycles.
3. 3-Byte transfer cases occur only as a result of a long word to 8-bit port transfer.
3.6 Chip-Selects
Typical microcontrollers require additional hardware to provide external chip-select and address decode signals. The MC68338 includes 12 programmable chip-selects that can provide 2 to 16-clock-cycle access to external memory and peripherals. Address block sizes of two Kbytes to one Mbyte can be
selected. Figure 11 is a functional diagram of a chip-select circuit.
Chip-select assertion can be synchronized with bus control signals to provide output enable, read/write
strobe, or interrupt acknowledge signals. Chip-select logic can also generate DSACK and AVEC signals
internally. Each signal can also be synchronized with the ECLK signal available on ADDR23.
INTERNAL
SIGNALS
BASE ADDRESS REGISTER
ADDRESS
ADDRESS COMPARATOR
BUS CONTROL
TIMING
AND
CONTROL
PIN
OPTION COMPARE
OPTION REGISTER
AVEC
AVEC
GENERATOR
DSACK
GENERATOR
PIN
ASSIGNMENT
REGISTER
PIN
DATA
REGISTER
DSACK
CHIP SEL BLOCK
Figure 11 Chip-Select Circuit Block Diagram
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When a memory access occurs, chip-select logic compares address space type, address, type of access, transfer size, and interrupt priority (in the case of interrupt acknowledge) to parameters stored in
chip-select registers. If all parameters match, the appropriate chip-select signal is asserted. Select signals are active low. If a chip-select function is given the same address as a microcontroller module or
an internal memory array, an access to that address goes to the module or array, and the chip-select
signal is not asserted. The external address and data buses do not reflect the internal access.
All chip-select circuits except CSBOOT are disabled out of reset. Chip-select option registers must not
be written until base addresses have been written to the proper base address registers. Alternate functions for chip-select pins are enabled if appropriate data bus pins are held low at the release of RESET.
Table 17 lists allocation of chip-selects and discrete outputs on the pins of the MCU.
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Table 17 Chip-Select and Discrete Output Allocation
Pin
Chip-Select
Discrete Outputs
CSBOOT
CSBOOT
—
BR
CS0
—
BG
CS1
—
BGACK
CS2
—
FC0
CS3
PC0
FC1
CS4
PC1
FC2
CS5
PC2
ADDR19
CS6
PC3
ADDR20
CS7
PC4
ADDR21
CS8
PC5
ADDR22
CS9
PC6
ADDR23
CS10
—
3.6.1 Chip-Select Registers
Each chip-select pin can have one or more functions. Chip-select pin assignment registers CSPAR[0:1]
determine functions of the pins. Pin assignment registers also determine port size for dynamic bus allocation. A pin data register (PORTC) latches data for chip-select pins that are used for discrete output.
Blocks of addresses are assigned to each chip-select function. Block sizes of two Kbytes to one Mbyte
can be selected by writing values to the appropriate base address registers CSBARBT and CSBAR[0:10]. Multiple chip-selects assigned to the same block of addresses must have the same number
of wait states.
Chip-select option registers CSORBT and CSOR[0:10] determine timing of and conditions for assertion
of chip-select signals. Eight parameters, including operating mode, access size, synchronization, and
wait state insertion can be specified.
Initialization software usually resides in a peripheral memory device controlled by the chip-select circuits. CSBOOT and registers CSORBT and CSBARBT are provided to support bootstrap operation.
3.6.2 Pin Assignment Registers
The pin assignment registers contain twelve 2-bit fields that determine functions of the chip-select pins.
Each pin has two or three possible functions, as shown in Table 18.
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Table 18 Chip-Select Pin Functions
Assignment
Register
16-Bit
Chip-Select
Alternate
Function
Discrete
Output
CSBOOT
CSBOOT
—
CS0
BR
—
CS1
BG
—
CS2
BGACK
—
CS3
FC0
PC0
CS4
FC1
PC1
CS5
FC2
PC2
CS6
ADDR19
PC3
CS7
ADDR20
PC4
CS8
ADDR21
PC5
CS9
ADDR22
PC6
CS10
ADDR23
ECLK
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CSPAR0
CSPAR1
Table 19 shows pin assignment field encoding. Pins that have no discrete output function do not use
the %00 encoding.
Table 19 Pin Assignment Encodings
Bit Field
Description
00
Discrete output
01
Alternate function
10
Chip-select (8-bit port)
11
Chip-select (16-bit port)
CSPAR0 — Chip-Select Pin Assignment Register 0
15
14
13
0
0
CS5PA[1:0]
12
11
10
CS4PA[1:0]
9
8
CS3PA[1:0]
$YFFA44
7
6
CS2PA[1:0]
5
4
CS1PA[1:0]
3
2
CS0PA[1:0]
1
0
CSBTPA[1:0]
RESET:
0
0
DATA2
1
DATA2
1
DATA2
1
DATA1
1
DATA1
1
DATA1
1
1
DATA0
CSPAR0 contains seven 2-bit fields that determine the functions of corresponding chip-select pins.
CSPAR0[15:14] are not used. These bits always read zero; writes have no effect. CSPAR0 bit 1 always
reads one; writes to CSPAR0 bit 1 have no effect. Table 20 shows CSPAR0 pin assignments.
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Table 20 CSPAR0 Pin Assignments
CSPAR0 Field
Chip-Select Signal
Alternate Signal
Discrete Output
CS5PA[1:0]
CS5
FC2
PC2
CS4PA[1:0]
CS4
FC1
PC1
CS3PA[1:0]
CS3
FC0
PC0
CS2PA[1:0]
CS2
BGACK
—
CS1PA[1:0]
CS1
BG
—
CS0PA[1:0]
CS0
BR
—
CSBTPA[1:0]
CSBOOT
—
—
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CSPAR1 — Chip-Select Pin Assignment Register 1
15
14
13
12
11
10
0
0
0
0
0
0
0
0
0
0
0
9
$YFFA46
8
7
CS10PA[1:0]
6
CS9PA[1:0]
5
4
CS8PA[1:0]
3
2
1
CS7PA[1:0]
0
CS6PA[1:0]
RESET:
0
DATA71
1
DATA
[7:6]1
1
DATA
[7:5]1
1
DATA
[7:4]1
1
DATA
[7:3]1
1
NOTES:
1. Refer to Table 21 for CSPAR1 reset state information.
The reset state of DATA[7:3] determines whether pins controlled by CSPAR1 are initially configured as
high-order address lines or chip-selects. Table 21 shows the correspondence between DATA[7:3] and
the reset configuration of CS[10:6]/ADDR[23:19].
Table 21 Reset Pin Function of CS[10:6]
Data Bus Pins at Reset
Chip-Select/Address Bus Pin Function
CS9/
CS8/
CS7/
CS8/
CS10/
ADDR23 ADDR22 ADDR21 ADDR20 ADDR19
DATA7
DATA6
DATA5
DATA4
DATA3
1
1
1
1
1
CS10
CS9
CS8
CS7
CS6
1
1
1
1
0
CS10
CS9
CS8
CS7
ADDR19
1
1
1
0
X
CS10
CS9
1
1
0
X
X
CS10
CS9
1
0
X
X
X
CS10
0
X
X
X
X
CS8
ADDR20 ADDR19
ADDR21 ADDR20 ADDR19
ADDR22 ADDR21 ADDR20 ADDR19
ADDR23 ADDR22 ADDR21 ADDR20 ADDR19
CSPAR1 contains five 2-bit fields that determine the functions of corresponding chip-select pins.
CSPAR1[15:10] are not used. These bits always read zero; writes have no effect. Table 22 shows
CSPAR1 pin assignments.
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Table 22 CSPAR1 Pin Assignments
CSPAR1 Field
Chip-Select Signal
Alternate Signal
Discrete Output
CS10PA[1:0]
CS10
ADDR23
ECLK
CS9PA[1:0]
CS9
ADDR22
PC6
CS8PA[1:0]
CS8
ADDR21
PC5
CS7PA[1:0]
CS7
ADDR20
PC4
CS6PA[1:0]
CS6
ADDR19
PC3
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Port size determines the way in which bus transfers to external addresses are allocated. Port size of
eight bits or sixteen bits can be selected when a pin is assigned as a chip-select. Port size and transfer
size affect how the chip-select signal is asserted. Refer to 3.6.4 Option Registers for more information.
Out of reset, chip-select pin function is determined by the logic level on a corresponding data bus pin.
These pins have weak internal pull-up drivers, but can be held low by external devices. Either 16-bit
chip-select function (%11) or alternate function (%01) can be selected during reset. All pins except the
boot ROM select pin (CSBOOT) are disabled out of reset.
The CSBOOT signal is normally enabled out of reset. The state of the DATA0 line during reset determines what port width CSBOOT uses. If DATA0 is held high (either by the weak internal pull-up driver
or by an external pull-up device), 16-bit width is selected. If DATA0 is held low, 8-bit port size is selected.
A pin programmed as a discrete output drives an external signal to the value specified in the pin data
register. No discrete output function is available on pins CSBOOT, BR, BG, or BGACK. ADDR23 provides ECLK output rather than a discrete output signal.
When a pin is programmed for discrete output or alternate function, internal chip-select logic still functions and can be used to generate DSACK or AVEC internally on an address and control signal match.
3.6.3 Base Address Registers
Each chip-select has an associated base address register. A base address is the lowest address in the
block of addresses enabled by a chip-select. Block size is the extent of the address block above the
base address. Block size is determined by the value contained in a BLKSZ field. Multiple chip-selects
may be assigned to the same block of addresses so long as each chip-select uses the same number
of wait states.
The BLKSZ field determines which bits in the base address field are compared to corresponding bits on
the address bus during an access. Provided other constraints determined by option register fields are
also satisfied, when a match occurs, the associated chip-select signal is asserted.
After reset, the MCU fetches the address of the first instruction to be executed from the reset vector,
located beginning at address $000000 in program space. To support bootstrap operation from reset,
the base address field in CSBARBT has a reset value of all zeros. A memory device containing the reset
vector and an initialization routine can be automatically enabled by CSBOOT after a reset. The block
size field in CSBARBT has a reset value of one Mbyte.
CSBARBT — Chip-Select Base Address Register Boot ROM
$YFFA48
15
14
13
12
11
10
9
8
7
6
5
4
3
ADDR
23
ADDR
22
ADDR
21
ADDR
20
ADDR
19
ADDR
18
ADDR
17
ADDR
16
ADDR
15
ADDR
14
ADDR
13
ADDR
12
ADDR
11
0
0
0
0
0
0
0
0
0
0
0
2
1
0
BLKSZ[2:0]
RESET:
0
0
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CSBAR[0:10] — Chip-Select Base Address Registers
$YFFA4C–$YFFA74
15
14
13
12
11
10
9
8
7
6
5
4
3
ADDR
23
ADDR
22
ADDR
21
ADDR
20
ADDR
19
ADDR
18
ADDR
17
ADDR
16
ADDR
15
ADDR
14
ADDR
13
ADDR
12
ADDR
11
0
0
0
0
0
0
0
0
0
0
0
2
1
0
BLKSZ[2:0]
RESET:
0
0
0
0
0
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ADDR[23:11] — Base Address Field
This field sets the starting address of a particular chip-select’s address space. The address compare
logic uses only the most significant bits to match an address within a block. The value of the base address must be a multiple of the block size. The base address register diagrams above show how register
bits correspond to CPU address lines.
BLKSZ[2:0] — Block Size Field
This field determines the size of the block that must be enabled by the chip-select. Table 23 shows bit
encoding for the base address registers block size field.
Table 23 Block Size Field Bit Encoding
Block Size
Field
Block Size
Address Lines Compared
000
2 Kbyte
ADDR[23:11]
001
8 Kbyte
ADDR[23:13]
010
16 Kbyte
ADDR[23:14]
011
64 Kbyte
ADDR[23:16]
100
128 Kbyte
ADDR[23:17]
101
256 Kbyte
ADDR[23:18]
110
512 Kbyte
ADDR[23:19]
111
1 Mbyte
ADDR[23:20]
3.6.4 Option Registers
The option registers contain eight fields that determine timing of and conditions for assertion of chipselect signals. To assert a chip-select signal, and to provide DSACK or autovector support, other constraints set by fields in the option register and in the base address register must also be satisfied.
CSORBT — Chip-Select Option Register Boot ROM
15
14
MODE
13
BYTE[1:0]
12
11
R/W[1:0]
10
9
STRB
8
$YFFA4A
7
6
DSACK[3:0]
5
4
3
SPACE[1:0]
2
1
IPL[2:0]
0
AVEC
RESET:
0
1
1
1
1
0
1
1
0
1
1
1
0
CSOR[0:10] — Chip-Select Option Registers
15
14
MODE
13
BYTE[1:0]
12
11
R/W[1:0]
10
9
STRB
0
0
0
$YFFA4E–YFFA76
8
7
6
DSACK[3:0]
5
4
3
SPACE[1:0]
2
1
IPL[2:0]
0
AVEC
RESET:
0
0
0
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0
0
0
0
0
0
0
0
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0
0
0
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CSORBT, the option register for CSBOOT, contains special reset values that support bootstrap operation from peripheral memory devices.
The following bit descriptions apply to both CSORBT and CSOR[0:10] option registers.
MODE — Asynchronous/Synchronous Mode
0 = Asynchronous mode (chip-select assertion determined by bus control signals)
1 = Synchronous mode (chip-select assertion synchronized with ECLK signal)
In asynchronous mode, the chip-select is asserted synchronized with AS or DS.
DSACK[3:0] is not used in synchronous mode because a bus cycle is only performed as a synchronous
operation. When a match condition occurs on a chip-select programmed for synchronous operation, the
chip-select signals the EBI that an ECLK cycle is pending.
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BYTE[1:0] — Upper/Lower Byte Option
This field is used only when the chip-select 16-bit port option is selected in the pin assignment register.
Table 24 lists upper/lower byte options.
Table 24 Upper/Lower Byte Options
BYTE[1:0]
Description
00
Disable
01
Lower Byte
10
Upper Byte
11
Both Bytes
R/W[1:0] — Read/Write
This field causes a chip-select to be asserted only for reads, only for writes, or for both reads and writes.
Refer to Table 25 for options available.
Table 25 R/W Encodings
R/W[1:0]
Description
00
Reserved
01
Read Only
10
Write Only
11
Read/Write
STRB — Address Strobe/Data Strobe
0 = Address strobe
1 = Data strobe
This bit controls the timing for assertion of a chip-select in asynchronous mode. Selecting address
strobe causes chip-select to be asserted synchronized with address strobe. Selecting data strobe causes chip-select to be asserted synchronized with data strobe.
DSACK[3:0] — Data and Size Acknowledge
This field specifies the source of DSACK[3:0] in asynchronous mode. It also allows the user to adjust
bus timing with internal DSACK[3:0] generation by controlling the number of wait states that are inserted
to optimize bus speed in a particular application. Table 26 shows the DSACK[3:0] encoding. The fast
termination encoding (%1110) is used for two-cycle access to external memory.
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Table 26 DSACK Field Encoding
DSACK[3:0]
Clock Cycles Required
Per Access
Wait States
Per Access
0000
3
0 Wait States
0001
4
1 Wait State
0010
5
2 Wait States
0011
6
3 Wait States
0100
7
4 Wait States
0101
8
5 Wait States
0110
9
6 Wait States
0111
10
7 Wait States
1000
11
8 Wait States
1001
12
9 Wait States
1010
13
10 Wait States
1011
14
11 Wait States
1100
15
12 Wait States
1101
16
13 Wait States
1110
2
Fast Termination
1111
—
External DSACK
SPACE[1:0] — Address Space
Use this option field to select an address space for the chip-select logic. The CPU32L normally operates
in supervisor or user space, but interrupt acknowledge cycles must take place in CPU space. Table 27
shows address space bit encodings.
Table 27 Address Space Bit Encodings
SPACE[1:0]
Address Space
00
CPU Space
01
User Space
10
Supervisor Space
11
Supervisor/User Space
IPL[2:0] — Interrupt Priority Level
If the space field is set for CPU space, chip-select logic can be used for interrupt acknowledge. During
an interrupt acknowledge cycle, the priority level on address lines ADDR[3:1] is compared to the value
in IPL[2:0]. If the values are the same, a chip-select is asserted, provided that other option register conditions are met. Table 28 shows IPL[2:0] encoding.
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Table 28 Interrupt Priority Level Field Encoding
IPL[2:0]
Interrupt Priority Level
000
Any Level
001
1
010
2
011
3
100
4
101
5
110
6
111
7
This field only affects the response of chip-selects and does not affect interrupt recognition by the CPU.
Any level means that chip-select is asserted regardless of the level of the interrupt acknowledge cycle.
AVEC — Autovector Enable
0 = External interrupt vector enabled
1 = Autovector enabled
This field selects one of two methods of acquiring an interrupt vector number during an external interrupt
acknowledge cycle.
If the chip-select is configured to trigger on an interrupt acknowledge cycle (SPACE[1:0] = %00) and
the AVEC field is set to one, the chip-select circuit generates an internal AVEC signal in response to an
external interrupt cycle, and the SIML supplies an automatic vector number. Otherwise, the vector number must be supplied by the requesting device. An internal autovector is generated only in response to
interrupt requests from the SIML IRQ pins. Interrupt requests from other IMB modules are ignored.
The AVEC bit must not be used in synchronous mode, as autovector response timing can vary because
of ECLK synchronization.
3.6.5 Port C Data Register
Bit values in port C determine the state of chip-select pins used for discrete output. When a pin is assigned as a discrete output, the value in this register appears at the output. This is a read/write register.
Bit 7 is not used. Writing to this bit has no effect, and it always returns zero when read.
PORTC — Port C Data Register
15
14
13
12
11
$YFFA41
10
NOT USED
9
8
7
6
5
4
3
2
1
0
0
PC6
PC5
PC4
PC3
PC2
PC1
PC0
0
1
1
1
1
1
1
1
RESET:
3.7 General-Purpose Input/Output
SIML pins can be configured as two general-purpose I/O ports, E and F. The following paragraphs describe registers that control the ports.
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PORTE0, PORTE1— Port E Data Register
15
14
13
12
11
10
9
$YFFA11, YFFA13
8
NOT USED
7
6
5
4
3
2
1
0
PE7
PE6
PE5
PE4
PE3
PE2
PE1
PE0
U
U
U
U
U
U
U
U
RESET:
A write to the port E data register is stored in the internal data latch and, if any port E pin is configured
as an output, the value stored for that bit is driven on the pin. A read of the port E data register returns
the value at the pin only if the pin is configured as a discrete input. Otherwise, the value read is the value
stored in the register.
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The port E data register is a single register that can be accessed in two locations. When accessed at
$YFFA11, the register is referred to as PORTE0; when accessed at $YFFA13, the register is referred
to as PORTE1. The register can be read or written at any time. It is unaffected by reset.
DDRE — Port E Data Direction Register
15
14
13
12
11
10
$YFFA15
9
8
7
6
5
4
3
2
1
0
DDE7
DDE6
DDE5
DDE4
DDE3
DDE2
DDE1
DDE0
0
0
0
0
0
0
0
0
RESET:
The bits in this register control the direction of the pin drivers when the pins are configured as I/O. Any
bit in this register set to one configures the corresponding pin as an output. Any bit in this register
cleared to zero configures the corresponding pin as an input. This register can be read or written at any
time.
PEPAR — Port E Pin Assignment
15
14
13
12
11
$YFFA17
10
9
8
7
6
5
4
3
2
1
0
PEPA7
PEPA6
PEPA5
PEPA4
PEPA3
PEPA2
PEPA1
PEPA0
DATA8
DATA8
DATA8
DATA8
DATA8
DATA8
DATA8
DATA8
RESET:
The bits in this register control the function of each port E pin. Any bit set to one configures the corresponding pin as a bus control signal, with the function shown in Table 29. Any bit cleared to zero defines
the corresponding pin to be an I/O pin, controlled by PORTE and DDRE.
Data bus bit 8 controls the state of this register following reset. If DATA8 is set to one during reset, the
register is set to $FF, which defines all port E pins as bus control signals. If DATA8 is cleared to zero
during reset, this register is set to $00, configuring all port E pins as I/O pins.
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Table 29 Port E Pin Assignments
PEPAR Bit
Port E Signal
Bus Control Signal
PEPA7
PE7
SIZ1
PEPA6
PE6
SIZ0
PEPA5
PE5
AS
PEPA4
PE4
DS
PEPA3
PE3
RMC
PEPA2
PE2
AVEC
PEPA1
PE1
DSACK1
PEPA0
PE0
DSACK0
PORTF0, PORTF1 — Port F Data Register
15
14
13
12
11
10
9
$YFFA19, YFFA1B
8
NOT USED
7
6
5
4
3
2
1
0
PF7
PF6
PF5
PF4
PF3
PF2
PF1
PF0
U
U
U
U
U
U
U
U
RESET:
The write to the port F data register is stored in the internal data latch, and if any port F pin is configured
as an output, the value stored for that bit is driven onto the pin. A read of the port F data register returns
the value at the pin only if the pin is configured as a discrete input. Otherwise, the value read is the value
stored in the register.
The port F data register is a single register that can be accessed in two locations. When accessed at
$YFFA19, the register is referred to as PORTF0; when accessed at $YFFA1B, the register is referred
to as PORTF1. The register can be read or written at any time. It is unaffected by reset.
DDRF — Port F Data Direction Register
15
14
13
12
11
10
$YFFA1D
9
8
NOT USED
7
6
5
4
3
2
1
0
DDF7
DDF6
DDF5
DDF4
DDF3
DDF2
DDF1
DDF0
0
0
0
0
0
0
0
0
RESET:
The bits in this register control the direction of the pin drivers when the pins are configured as I/O. Any
bit in this register set to one configures the corresponding pin as an output. Any bit in this register
cleared to zero configures the corresponding pin as an input. This register can be read or written at any
time.
PFPAR — Port F Pin Assignment Register
15
14
13
12
11
NOT USED
10
9
$YFFA1F
8
7
6
5
4
3
2
1
0
PFPA7
PFPA6
PFPA5
PFPA4
PFPA3
PFPA2
PFPA1
PFPA0
DATA9
DATA9
DATA9
DATA9
DATA9
DATA9
DATA9
DATA9
RESET:
The bits in this register control the function of each port F pin. Any bit cleared to zero defines the corresponding pin to be an I/O pin. Any bit set to one defines the corresponding pin to be an interrupt request
signal or MODCLK. The MODCLK signal has no function after reset. Table 30 shows port F pin
assignments.
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Table 30 Port F Pin Assignments
PFPAR Field
Port F Signal
Alternate Signal
PFPA7
PF7
IRQ7
PFPA6
PF6
IRQ6
PFPA5
PF5
IRQ5
PFPA4
PF4
IRQ4
PFPA3
PF3
IRQ3
PFPA2
PF2
IRQ2
PFPA1
PF1
IRQ1
PFPA0
PF0
MODCLK
Data bus pin 9 controls the state of this register following reset. If DATA9 is set to one during reset, the
register is set to $FF, which defines all port F pins as interrupt request inputs. If DATA9 is cleared to
zero during reset, this register is set to $00, defining all port F pins as I/O pins.
3.8 Resets
Reset procedures handle system initialization and recovery from catastrophic failure. The MCU performs resets with a combination of hardware and software. The SIML determines whether a reset is valid, asserts control signals, performs basic system configuration based on hardware mode-select inputs,
then passes control to the CPU.
Reset occurs when an active low logic level on the RESET pin is clocked into the SIML. Resets are gated by the CLKOUT signal. Asynchronous resets are assumed to be catastrophic. An asynchronous reset can occur on any clock edge. Synchronous resets are timed to occur at the end of bus cycles. If
there is no clock when RESET is asserted, reset does not occur until the clock starts. Resets are
clocked in order to allow completion of write cycles in progress at the time RESET is asserted.
Reset is the highest-priority CPU32L exception. Any processing in progress is aborted by the reset exception, and cannot be restarted. Only essential tasks are performed during reset exception processing.
Other initialization tasks must be accomplished by the exception handler routine.
3.8.1 SIML Reset Mode Selection
The logic states of certain data bus pins during reset determine SIML operating configuration. In addition, the state of the MODCLK pin determines system clock source and the state of the BKPT pin determines what happens during subsequent breakpoint assertions. Table 31 is a summary of reset mode
selection options.
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Table 31 Reset Mode Selection
Mode Select Pin
Default Function
(Pin Left High)
Alternate Function
(Pin Pulled Low)
DATA0
CSBOOT 16-Bit
CSBOOT 8-Bit
DATA1
CS0
CS1
CS2
BR
BG
BGACK
DATA2
CS3
CS4
CS5
FC0
FC1
FC2
DATA3
DATA4
DATA5
DATA6
DATA7
CS6
CS[7:6]
CS[8:6]
CS[9:6]
CS[10:6]
ADDR19
ADDR[20:19]
ADDR[21:19]
ADDR[22:19]
ADDR[23:19]
DATA8
DSACK[1:0]
AVEC, DS, AS
SIZ[1:0]
PORTE
DATA9
IRQ[7:1]
MODCLK
PORTF
DATA11
Test Mode Disabled
Test Mode Enabled
MODCLK
VCO = System Clock
EXTAL = System Clock
BKPT
Background Mode Disabled
Background Mode Enabled
Data lines have weak internal pull-up drivers. External bus loading can overcome the weak internal pullup drivers on data bus lines, and hold pins low during reset. Use an active device to hold data bus lines
low. Data bus configuration logic must release the bus before the first bus cycle after reset to prevent
conflict with external memory devices. The first bus cycle occurs ten CLKOUT cycles after RESET is
released. If external mode selection logic causes a conflict of this type, an isolation resistor on the driven
lines may be required.
3.8.2 Reset States of SIML Pins
Generally, while RESET is asserted, SIML pins either go to an inactive high-impedance state or are
driven to their inactive states. After RESET is released, mode selection occurs and reset exception processing begins. Pins configured as inputs must be driven to the desired active state. Pull-up or pulldown circuitry may be necessary. Pins configured as outputs begin to function after RESET is released.
Table 32 is a summary of SIML pin states during reset.
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Table 32 SIML Pin Reset States
Pin State After RESET Released
Pin(s)
Pin State
While RESET
Asserted
Pin Function
Pin State
Pin Function
Pin State
CS10/ADDR23/ECLK
VDD
CS10
VDD
ADDR23
Unknown
CS[9:6]/ADDR[22:19]/PC[6:3]
VDD
CS[9:6]
VDD
ADDR[22:19]
Unknown
ADDR[18:0]
High-Z
ADDR[18:0]
Unknown
ADDR[18:0]
Unknown
AS/PE5
High-Z
AS
Output
PE5
Input
AVEC/PE2
High-Z
AVEC
Input
PE2
Input
BERR
High-Z
BERR
Input
BERR
Input
CS1/BG
VDD
CS1
VDD
BG
VDD
CS2/BGACK
VDD
CS2
VDD
BGACK
Input
CS0/BR
VDD
CS0
VDD
BR
Input
CLKOUT
Output
CLKOUT
Output
CLKOUT
Output
CSBOOT
VDD
CSBOOT
VSS
CSBOOT
VSS
DATA[15:0]
Mode select
DATA[15:0]
Input
DATA[15:0]
Input
Default Function
Alternate Function
DS/PE4
High-Z
DS
Output
PE4
Input
DSACK0/PE0
High-Z
DSACK0
Input
PE0
Input
DSACK1/PE1
High-Z
DSACK1
Input
PE1
Input
CS[5:3]/FC[2:0]/PC[2:0]
VDD
CS[5:3]
VDD
FC[2:0]
Unknown
HALT
High-Z
HALT
Input
HALT
Input
IRQ[7:1]/PF[7:1]
High-Z
IRQ[7:1]
Input
PF[7:1]
Input
MODCLK/PF0
Mode Select
MODCLK
Input
PF0
Input
R/W
High-Z
R/W
Output
R/W
Output
RESET
Asserted
RESET
Input
RESET
Input
RMC/PE3
High-Z
RMC
Output
PE3
Input
SIZ[1:0]/PE[7:6]
High-Z
SIZ[1:0]
Unknown
PE[7:6]
Input
TSC
Mode select
TSC
Input
TSC
Input
3.8.3 Functions of Pins for Other Modules During Reset
Generally, pins associated with modules other than the SIML default to port functions, and input/output
ports are set to input state. This is accomplished by disabling pin functions in the appropriate control
registers, and by clearing the appropriate port data direction registers. Refer to individual module sections in this manual for more information.
3.8.4 Reset Timing
The RESET input must be asserted for a specified minimum period in order for reset to occur. External
RESET assertion can be delayed internally for a period equal to the longest bus cycle time (or the bus
monitor time-out period) in order to protect write cycles from being aborted by reset. While RESET is
asserted, SIML pins are either in a disabled high-impedance state or are driven to their inactive states.
When an external device asserts RESET for the proper period, reset control logic clocks the signal into
an internal latch. The control logic drives the RESET pin low for an additional 512 CLKOUT cycles after
it detects that the RESET signal is no longer being externally driven, to guarantee this length of reset
to the entire system.
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If an internal source asserts the reset signal, the reset control logic asserts RESET for a minimum of
512 cycles. If the reset signal is still asserted at the end of 512 cycles, the control logic continues to
assert RESET until the internal reset signal is negated.
After 512 cycles have elapsed, the reset input pin goes to an inactive, high-impedance state for 10 cycles. At the end of this 10-cycle period, the reset input is tested. When the input is at logic level one,
reset exception processing begins. If, however, the reset input is at logic level zero, the reset control
logic drives the pin low for another 512 cycles. At the end of this period, the pin again goes to highimpedance state for ten cycles, then it is tested again. The process repeats until RESET is released.
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3.8.5 Power-On Reset
When the SIML clock synthesizer is used to generate the system clock, power-on reset involves special
circumstances related to application of system and clock synthesizer power. Regardless of clock
source, voltage must be applied to clock synthesizer power input pin VDDSYN in order for the MCU to
operate. The following discussion assumes that VDDSYN is applied before and during reset. This minimizes crystal start-up time. When VDDSYN is applied at power-on, start-up time is affected by specific
crystal parameters and by oscillator circuit design. VDD ramp-up time also affects pin state during reset.
During power-on reset, an internal circuit in the SIML drives the IMB and external reset lines. The circuit
releases the internal reset line as VDD ramps up to the minimum specified value, and SIML pins are
initialized. As VDD reaches a specified minimum value, the clock synthesizer VCO begins operation and
clock frequency ramps up to specified limp mode frequency. The external RESET line remains asserted
until the clock synthesizer PLL locks and 512 CLKOUT cycles elapse.
The SIML clock synthesizer provides clock signals to the other MCU modules. After the clock is running
and the internal reset signal is asserted for four clock cycles, these modules reset. VDD ramp time and
VCO frequency ramp time determine how long these four cycles take. Worst case is approximately 15
milliseconds. During this period, module port pins may be in an indeterminate state. While input-only
pins can be put in a known state by means of external pull-up resistors, external logic on input/output
or output-only pins must condition the lines during this time. Active drivers require high-impedance buffers or isolation resistors to prevent conflict.
3.8.6 Use of Three-State Control Pin
Asserting the three-state control (TSC) input causes the MCU to put all output drivers in an inactive,
high-impedance state. The signal must remain asserted for ten clock cycles in order for drivers to
change state. There are certain constraints on use of TSC during power-on reset:
• When the internal clock synthesizer is used (MODCLK held high during reset), synthesizer rampup time affects how long the ten cycles take. Worst case is approximately 20 ms from TSC assertion.
• When an external clock signal is applied (MODCLK held low during reset), pins go to high-impedance state as soon after TSC assertion as ten clock pulses have been applied to the EXTAL pin.
• When TSC assertion takes effect, internal signals are forced to values that can cause inadvertent
mode selection. Once the output drivers change state, the MCU must be powered down and restarted before normal operation can resume.
3.9 Interrupts
Interrupt recognition and servicing involve complex interaction between the CPU32L, the SIML, and a
device or module requesting interrupt service.
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The CPU32L provides seven levels of interrupt priority (1–7), seven automatic interrupt vectors, and
200 assignable interrupt vectors. All interrupts with priorities less than seven can be masked by the interrupt priority (IP) field in status register. The CPU32L handles interrupts as a type of asynchronous
expression.
There are seven interrupt request signals (IRQ[7:1]). These signals are used internally on the IMB, and
there are corresponding pins for external interrupt service requests. The CPU treats all interrupt requests as though they come from internal modules — external interrupt requests are treated as interrupt
service requests from the SIML. Each of the interrupt request signals corresponds to an interrupt priority
level. IRQ1 has the lowest priority and IRQ7 the highest.
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Interrupt recognition is determined by interrupt priority level and interrupt priority mask value. The interrupt priority mask consists of three bits in the CPU32L status register. Binary values %000 to %111 provide eight priority masks. Masks prevent an interrupt request of a priority less than or equal to the mask
value from being recognized and processed. IRQ7, however, is always recognized, even if the mask
value is %111.
IRQ[7:1] are active-low level-sensitive inputs. The low on the pin must remain asserted until an interrupt
acknowledge cycle corresponding to that level is detected.
IRQ7 is transition-sensitive as well as level-sensitive: a level 7 interrupt is not detected unless a falling
edge transition is detected on the IRQ7 line. This prevents redundant servicing and stack overflow. A
non-maskable interrupt is generated each time IRQ7 is asserted as well as each time the priority mask
changes from %111 to a lower number while IRQ7 is asserted.
Interrupt requests are sampled on consecutive falling edges of the system clock. Interrupt request input
circuitry has hysteresis: to be valid, a request signal must be asserted for at least two consecutive clock
periods. Valid requests do not cause immediate exception processing, but are left pending. Pending requests are processed at instruction boundaries or when exception processing of higher-priority exceptions is complete.
The CPU32L does not latch the priority of a pending interrupt request. If an interrupt source of higher
priority makes a service request while a lower priority request is pending, the higher priority request is
serviced. If an interrupt request with a priority equal to or lower than the current IP mask value is made,
the CPU32L does not recognize the occurrence of the request. If simultaneous interrupt requests of different priorities are made, and both have a priority greater than the mask value, the CPU32L recognizes
the higher-level request.
3.9.1 Interrupt Acknowledge and Arbitration
When the CPU32L detects one or more interrupt requests of a priority higher than the interrupt priority
mask value, it places the interrupt request level on the address bus and initiates a CPU space read cycle. The request level serves two purposes: it is decoded by modules or external devices that have requested interrupt service, to determine whether the current interrupt acknowledge cycle pertains to
them, and it is latched into the interrupt priority mask field in the CPU32L status register, to preclude
further interrupts of lower priority during interrupt service.
Modules or external devices that have requested interrupt service must decode the interrupt priority
mask value placed on the address bus during the interrupt acknowledge cycle and respond if the priority
of the service request corresponds to the mask value. However, before modules or external devices
respond, interrupt arbitration takes place.
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Arbitration is performed by means of serial contention between values stored in individual module interrupt arbitration (IARB) fields. Each module that can make an interrupt service request, including the
SIML, has an IARB field in its configuration register. IARB fields can be assigned values from %0000
to %1111. In order to implement an arbitration scheme, each module that can initiate an interrupt service request must be assigned a unique, non-zero IARB field value during system initialization. Arbitration priorities range from %0001 (lowest) to %1111 (highest) — if the CPU recognizes an interrupt
service request from a source that has an IARB field value of %0000, a spurious interrupt exception is
processed.
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WARNING
Do not assign the same arbitration priority to more than one module. When two or
more IARB fields have the same non-zero value, the CPU32L interprets multiple
vector numbers at the same time, with unpredictable consequences.
Because the EBI manages external interrupt requests, the SIML IARB value is used for arbitration between internal and external interrupt requests. The reset value of IARB for the SIML is %1111, and the
reset IARB value for all other modules is %0000.
Although arbitration is intended to deal with simultaneous requests of the same priority, it always takes
place, even when a single source is requesting service. This is important for two reasons: the EBI does
not transfer the interrupt acknowledge read cycle to the external bus unless the SIML wins contention,
and failure to contend causes the interrupt acknowledge bus cycle to be terminated early, by a bus error.
When arbitration is complete, the module with the highest arbitration priority must terminate the bus
cycle. Internal modules place an interrupt vector number on the data bus and generate appropriate internal cycle termination signals. In the case of an external interrupt request, after the interrupt acknowledge cycle is transferred to the external bus, the appropriate external device must decode the mask
value and respond with a vector number, then generate data and size acknowledge (DSACK) termination signals, or it must assert the autovector (AVEC) request signal. If the device does not respond in
time, the EBI bus monitor asserts the bus error signal (BERR), and a spurious interrupt exception is
taken.
Chip-select logic can also be used to generate internal AVEC or DSACK signals in response to interrupt
requests from external devices. Chip-select address match logic functions only after the EBI transfers
an interrupt acknowledge cycle to the external bus following IARB contention. If a module makes an
interrupt request of a certain priority, and the appropriate chip-select registers are programmed to generate AVEC or DSACK signals in response to an interrupt acknowledge cycle for that priority level, chipselect logic does not respond to the interrupt acknowledge cycle, and the internal module supplies a
vector number and generates internal cycle termination signals.
For periodic timer interrupts, the PIRQL field in the periodic interrupt control register (PICR) determines
PIT priority level. A PIRQL value of %000 means that PIT interrupts are inactive. By hardware convention, when the CPU32L receives simultaneous interrupt requests of the same level from more than one
SIML source (including external devices), the periodic interrupt timer is given the highest priority, followed by the IRQ pins. Refer to 3.4.6 Periodic Interrupt Timer for more information.
3.9.2 Interrupt Processing Summary
A summary of the interrupt processing sequence follows. When the sequence begins, a valid interrupt
service request has been detected and is pending.
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A. The CPU finishes higher priority exception processing or reaches an instruction boundary.
B. The processor state is stacked. The S bit in the status register is set, establishing supervisor
access level, and bits T1 and T0 are cleared, disabling tracing.
C. The interrupt acknowledge cycle begins:
1. FC[2:0] are driven to %111 (CPU space) encoding.
2. The address bus is driven as follows: ADDR[23:20] = %1111; ADDR[19:16] = %1111,
which indicates that the cycle is an interrupt acknowledge CPU space cycle; ADDR[15:4]
= %111111111111; ADDR[3:1] = the priority of the interrupt request being acknowledged;
and ADDR0 = %1.
3. The request level is latched from the address bus into the interrupt priority mask field in the
status or condition code register.
D. Modules that have requested interrupt service decode the priority value on ADDR[3:1]. If
request priority is the same as acknowledged priority, arbitration by IARB contention takes
place.
E. After arbitration, the interrupt acknowledge cycle is completed in one of the following ways:
1. When there is no contention (IARB = %0000), the spurious interrupt monitor asserts BERR,
and the CPU generates the spurious interrupt vector number.
2. The dominant interrupt source supplies a vector number and DSACK signals appropriate
to the access. The CPU acquires the vector number.
3. The AVEC signal is asserted (the signal can be asserted by the dominant interrupt source
or the pin can be tied low), and the CPU generates an autovector number corresponding
to interrupt priority.
4. The bus monitor asserts BERR and the CPU32L generates the spurious interrupt vector
number.
F. The vector number is converted to a vector address.
G. The content of the vector address is loaded into the PC, and the processor transfers control to
the exception handler routine.
3.10 Factory Test Block
The test submodule supports scan-based testing of the various MCU modules. It is integrated into the
SIML to support production testing.
Test submodule registers are intended for Motorola use. Register names and addresses are provided
to indicate that these addresses are occupied.
SIMLTR — System Integration Module Test Register
$YFFA02
SIMLTRE — System Integration Module Test Register (E Clock)
$YFFA08
TSTMSRA — Master Shift Register A
$YFFA30
TSTMSRB — Master Shift Register B
$YFFA32
TSTSC — Test Module Shift Count
$YFFA34
TSTRC — Test Module Repetition Count
$YFFA36
CREG — Test Module Control Register
$YFFA38
DREG — Test Module Distributed Register
$YFFA3A
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4 Low-Power Central Processor Unit
Based on the powerful MC68020, the CPU32L processing module provides enhanced system performance and also uses the extensive software base for the Motorola M68000 family.
4.1 Overview
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The CPU32L is fully object-code compatible with the M68000 family, which excels at processing calculation-intensive algorithms and supporting high-level languages. The CPU32L supports all of the
MC68010 and most of the MC68020 enhancements, such as virtual memory support, loop mode operation, instruction pipeline, and 32-bit mathematical operations. Powerful addressing modes provide
compatibility with existing software programs and increase the efficiency of high-level language compilers. Special instructions, such as table lookup and interpolate and low-power stop, support the specific
requirements of controller applications. Also included is background debug mode, an alternate operating mode that suspends normal operation and allows the CPU to accept debugging commands from
the development system.
Ease of programming is an important consideration in using a microcontroller. The CPU32L instruction
set is optimized for high performance. The eight 32-bit general-purpose data registers readily support
8-bit (byte), 16-bit (word), and 32-bit (long word) operations. Ease of program checking and diagnosis
is further enhanced by trace and trap capabilities at the instruction level.
Use of high-level languages is increasing as controller applications become more complex and control
programs become larger. High-level languages aid rapid development of software, with less error, and
are readily portable. The CPU32L instruction set supports high-level languages.
4.2 Programming Model
The CPU32L has sixteen 32-bit general registers, a 32-bit program counter, one 32-bit supervisor stack
pointer, a 16-bit status register, two alternate function code registers, and a 32-bit vector base register.
The programming model of the CPU32L consists of a user model shown in Figure 12 and a supervisor
model shown in Figure 13, corresponding to the user and supervisor privilege levels. Some instructions
available at the supervisor level are not available at the user level, allowing the supervisor to protect
system resources from uncontrolled access. Bit S in the status register determines the privilege level.
The user programming model remains unchanged from previous M68000 family microprocessors. Application software written to run at the nonprivileged user level migrates without modification to the
CPU32L from any M68000 platform. The move from SR instruction, however, is privileged in the
CPU32L. It is not privileged in the M68000.
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31
16 15
87
0
D0
D1
D2
D3
DATA REGISTERS
D4
D5
D6
D7
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31
16 15
0
A0
A1
A2
A3
ADDRESS REGISTERS
A4
A5
A6
31
16 15
0
31
A7 (SSP)
USER STACK POINTER
PC
PROGRAM COUNTER
0
7
0
CCR
CONDITION CODE REGISTER
CPU32 USER PROG MODEL
Figure 12 User Programming Model
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31
16 15
0
A7’ (SSP) SUPERVISOR STACK POINTER
15
87
0
(CCR)
31
SR
STATUS REGISTER
VBR
VECTOR BASE REGISTER
SFC
ALTERNATE FUNCTION
DFC
CODE REGISTERS
0
0
2
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CPU32 SUPV PROG MODEL
Figure 13 Supervisor Programming Model Supplement
4.3 Status Register
The status register contains the condition codes that reflect the results of a previous operation and can
be used for conditional instruction execution in a program. The lower byte containing the condition
codes is the only portion of the register available at the user privilege level; it is referenced as the condition code register (CCR) in user programs. At the supervisor privilege level, software can access the
full status register, including the interrupt priority mask and additional control bits.
SR — Status Register
15
14
13
12
11
T1
T0
S
0
0
1
0
0
10
9
8
IP
7
6
5
4
3
2
1
0
0
0
0
X
N
Z
V
C
0
0
0
U
U
U
U
U
RESET:
0
0
1
1
1
System Byte
T[1:0] — Trace Enable
S — Supervisor/User State
Bits [12:11] — Unimplemented
IP[2:0] — Interrupt Priority Mask
User Byte (Condition Code Register)
Bits [7:5] — Unimplemented
X — Extend
N — Negative
Z — Zero
V — Overflow
C — Carry
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4.4 Data Types
Six basic data types are supported:
• Bits
• Packed Binary Coded Decimal Digits
• Byte Integers (8 bits)
• Word Integers (16 bits)
• Long Word Integers (32 bits)
• Quad Word Integers (64 bits)
4.5 Addressing Modes
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Addressing in the CPU32L is register-oriented. Most instructions allow the results of the specified operation to be placed either in a register or directly in memory. This flexibility eliminates the need for extra
instructions to store register contents in memory. The CPU32L supports seven basic addressing
modes:
• Register direct
• Register indirect
• Register indirect with index
• Program counter indirect with displacement
• Program counter indirect with index
• Absolute
• Immediate
Included in the register indirect addressing modes are the capabilities to post-increment, predecrement,
and offset. The program counter relative mode also has index and offset capabilities. In addition to
these addressing modes, many instructions implicitly specify the use of the status register, stack pointer, or program counter.
4.6 Instruction Set Summary
Table 33 provides a summary of the CPU32L instruction set.
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Table 33 Instruction Set Summary
Instruction
Syntax
Operand Size
Operation
ABCD
Dn, Dn
− (An), − (An)
8
8
ADD
Dn, <ea>
<ea>, Dn
8, 16, 32
8, 16, 32
Source + Destination ⇒ Destination
ADDA
<ea>, An
16, 32
Source + Destination ⇒ Destination
Source10 + Destination10 + X ⇒ Destination
ADDI
#<data>, <ea>
8, 16, 32
Immediate data + Destination ⇒ Destination
ADDQ
# <data>, <ea>
8, 16, 32
Immediate data + Destination ⇒ Destination
ADDX
Dn, Dn
− (An), − (An)
8, 16, 32
8, 16, 32
Source + Destination + X ⇒ Destination
AND
<ea>, Dn
Dn, <ea>
8, 16, 32
8, 16, 32
Source • Destination ⇒ Destination
ANDI
# <data>, <ea>
8, 16, 32
Data • Destination ⇒ Destination
# <data>, CCR
8
Source • CCR ⇒ CCR
ANDI to CCR
ANDI to SR1
# <data>, SR
16
Source • SR ⇒ SR
ASL
Dn, Dn
# <data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
X/C
ASR
Dn, Dn
# <data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
Bcc
label
8, 16, 32
BCHG
Dn, <ea>
# <data>, <ea>
8, 32
8, 32
BCLR
Dn, <ea>
# <data>, <ea>
8, 32
8, 32
BGND
none
none
If background mode enabled, then enter background
mode, else format/vector ⇒ − (SSP);
PC ⇒ − (SSP); SR ⇒ − (SSP); (vector) ⇒ PC
BKPT
# <data>
none
If breakpoint cycle acknowledged, then execute
returned operation word, else trap as illegal instruction
BRA
label
8, 16, 32
BSET
Dn, <ea>
# <data>, <ea>
8, 32
8, 32
BSR
label
8, 16, 32
BTST
Dn, <ea>
# <data>, <ea>
8, 32
8, 32
CHK
<ea>, Dn
16, 32
CHK2
<ea>, Rn
8, 16, 32
If Rn < lower bound or Rn > upper bound, then
CHK exception
CLR
<ea>
8, 16, 32
0 ⇒ Destination
CMP
<ea>, Dn
8, 16, 32
(Destination − Source), CCR shows results
(Destination − Source), CCR shows results
1
CMPA
<ea>, An
16, 32
CMPI
# <data>, <ea>
8, 16, 32
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0
X/C
If condition true, then PC + d ⇒ PC
( 〈 bit number〉 of destination ) ⇒ Z ⇒ bit of destination
( 〈 bit number〉 of destination ) ⇒ Z;
0 ⇒ bit of destination
PC + d ⇒ PC
( 〈 bit number〉 of destination ) ⇒ Z;
1 ⇒ bit of destination
SP − 4 ⇒ SP; PC ⇒ (SP); PC + d ⇒ PC
( 〈 bit number〉 of destination ) ⇒ Z
If Dn < 0 or Dn > (ea), then CHK exception
(Destination − Data), CCR shows results
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Table 33 Instruction Set Summary (Continued)
Instruction
Syntax
Operand Size
CMPM
(An) +, (An) +
8, 16, 32
(Destination − Source), CCR shows results
CMP2
<ea>, Rn
8, 16, 32
Lower bound ≤ Rn ≤ Upper bound, CCR shows result
DBcc
Dn, label
16
DIVS/DIVU
<ea>, Dn
32/16 ⇒ 16 : 16
Destination / Source ⇒ Destination
(signed or unsigned)
DIVSL/DIVUL
<ea>, Dr : Dq
<ea>, Dq
<ea>, Dr : Dq
64/32 ⇒ 32 : 32
32/32 ⇒ 32
32/32 ⇒ 32 : 32
Destination / Source ⇒ Destination
(signed or unsigned)
EOR
Dn, <ea>
8, 16, 32
Source ⊕ Destination ⇒ Destination
EORI
# <data>, <ea>
8, 16, 32
Data ⊕ Destination ⇒ Destination
# <data>, CCR
8
Source ⊕ CCR ⇒ CCR
EORI to SR
# <data>, SR
16
Source ⊕ SR ⇒ SR
EXG
Rn, Rn
32
Rn ⇒ Rn
EXT
Dn
Dn
8 ⇒ 16
16 ⇒ 32
Sign extended Destination ⇒ Destination
EXTB
Dn
8 ⇒ 32
Sign extended Destination ⇒ Destination
none
SSP − 2 ⇒ SSP; vector offset ⇒ (SSP);
SSP − 4 ⇒ SSP; PC ⇒ (SSP);
SSP − 2 ⇒ SSP; SR ⇒ (SSP);
Illegal instruction vector address ⇒ PC
EORI to CCR
1
ILLEGAL
none
Operation
If condition false, then Dn − 1 ⇒ PC;
if Dn ≠ (− 1), then PC + d ⇒ PC
JMP
<ea>
none
Destination ⇒ PC
JSR
<ea>
none
SP − 4 ⇒ SP; PC ⇒ (SP); destination ⇒ PC
LEA
<ea>, An
32
An, # d
16, 32
# <data>
16
LSL
Dn, Dn
# <data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
LSR
Dn, Dn
#<data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
MOVE
<ea>, <ea>
8, 16, 32
Source ⇒ Destination
MOVEA
<ea>, An
16, 32 ⇒ 32
Source ⇒ Destination
MOVEA1
USP, An
An, USP
32
32
USP ⇒ An
An ⇒ USP
MOVE from CCR
CCR, <ea>
16
CCR ⇒ Destination
MOVE to CCR
<ea>, CCR
16
Source ⇒ CCR
MOVE from SR1
SR, <ea>
16
SR ⇒ Destination
MOVE to SR1
<ea>, SR
16
Source ⇒ SR
MOVE USP1
USP, An
An, USP
32
32
USP ⇒ An
An ⇒ USP
MOVEC1
Rc, Rn
Rn, Rc
32
32
Rc ⇒ Rn
Rn ⇒ Rc
LINK
1, 2
LPSTOP
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<ea> ⇒ An
SP − 4 ⇒ SP, An ⇒ (SP); SP ⇒ An, SP + d ⇒ SP
Data ⇒ SR; interrupt mask ⇒ EBI; STOP
X/C
0
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X/C
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Table 33 Instruction Set Summary (Continued)
Instruction
Syntax
Operand Size
MOVEM
list, <ea>
<ea>, list
16, 32
16, 32 ⇒ 32
Dn [31 : 24] ⇒ (An + d); Dn [23 : 16] ⇒ (An + d + 2);
Dn [15 : 8] ⇒ (An + d + 4); Dn [7 : 0] ⇒ (An + d + 6)
Dn, (d16, An)
MOVEP
16, 32
(An + d) ⇒ Dn [31 : 24]; (An + d + 2) ⇒ Dn [23 : 16];
(An + d + 4) ⇒ Dn [15 : 8]; (An + d + 6) ⇒ Dn [7 : 0]
(d16, An), Dn
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Operation
Listed registers ⇒ Destination
Source ⇒ Listed registers
8 ⇒ 32
Immediate data ⇒ Destination
MOVEQ
#<data>, Dn
MOVES1
Rn, <ea>
<ea>, Rn
8, 16, 32
MULS/MULU
<ea>, Dn
<ea>, Dl
<ea>, Dh : Dl
16 ∗ 16 ⇒ 32
32 ∗ 32 ⇒ 32
32 ∗ 32 ⇒ 64
Source ∗ Destination ⇒ Destination
(signed or unsigned)
NBCD
<ea>
8
8
0 − Destination10 − X ⇒ Destination
NEG
<ea>
8, 16, 32
0 − Destination ⇒ Destination
NEGX
<ea>
8, 16, 32
0 − Destination − X ⇒ Destination
NOP
none
none
NOT
<ea>
8, 16, 32
Destination ⇒ Destination
OR
<ea>, Dn
Dn, <ea>
8, 16, 32
8, 16, 32
Source + Destination ⇒ Destination
ORI
#<data>, <ea>
8, 16, 32
Data + Destination ⇒ Destination
#<data>, CCR
16
Source + CCR ⇒ SR
ORI to SR
#<data>, SR
16
Source ; SR ⇒ SR
PEA
<ea>
32
SP − 4 ⇒ SP; <ea> ⇒ SP
RESET1
none
none
ROL
Dn, Dn
#<data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
ROR
Dn, Dn
#<data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
ROXL
Dn, Dn
#<data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
ROXR
Dn, Dn
#<data>, Dn
<ea>
8, 16, 32
8, 16, 32
16
RTD
#d
16
ORI to CCR
1
Rn ⇒ Destination using DFC
Source using SFC ⇒ Rn
PC + 2 ⇒ PC
Assert RESET line
C
C
C
X
X
C
(SP) ⇒ PC; SP + 4 + d ⇒ SP
RTE1
none
none
(SP) ⇒ SR; SP + 2 ⇒ SP; (SP) ⇒ PC;
SP + 4 ⇒ SP;
Restore stack according to format
RTR
none
none
(SP) ⇒ CCR; SP + 2 ⇒ SP; (SP) ⇒ PC;
SP + 4 ⇒ SP
RTS
none
none
(SP) ⇒ PC; SP + 4 ⇒ SP
SBCD
Dn, Dn
− (An), − (An)
8
8
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Destination10 − Source10 − X ⇒ Destination
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Table 33 Instruction Set Summary (Continued)
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Instruction
Syntax
Operand Size
Operation
Scc
<ea>
8
If condition true, then destination bits are set to 1;
else, destination bits are cleared to 0
STOP1
#<data>
16
Data ⇒ SR; STOP
SUB
<ea>, Dn
Dn, <ea>
8, 16, 32
Destination − Source ⇒ Destination
Destination − Source ⇒ Destination
SUBA
<ea>, An
16, 32
SUBI
#<data>, <ea>
8, 16, 32
Destination − Data ⇒ Destination
SUBQ
#<data>, <ea>
8, 16, 32
Destination − Data ⇒ Destination
SUBX
Dn, Dn
− (An), − (An)
8, 16, 32
8, 16, 32
Destination − Source − X ⇒ Destination
SWAP
Dn
16
TAS
<ea>
8
TBLS/TBLU
<ea>, Dn
Dym : Dyn, Dn
8, 16, 32
Dyn − Dym ⇒ Temp
(Temp ∗ Dn [7 : 0]) ⇒ Temp
(Dym ∗ 256) + Temp ⇒ Dn
TBLSN/TBLUN
<ea>, Dn
Dym : Dyn, Dn
8, 16, 32
Dyn − Dym ⇒ Temp
(Temp ∗ Dn [7 : 0]) / 256 ⇒ Temp
Dym + Temp ⇒ Dn
TRAP
#<data>
none
SSP − 2 ⇒ SSP; format/vector offset ⇒ (SSP);
SSP − 4 ⇒ SSP; PC ⇒ (SSP); SR ⇒ (SSP);
vector address ⇒ PC
TRAPcc
none
#<data>
none
16, 32
If cc true, then TRAP exception
If V set, then overflow TRAP exception
TRAPV
none
none
TST
<ea>
8, 16, 32
UNLK
An
32
MSW
LSW
Destination Tested Condition Codes bit 7 of
Destination
Source − 0, to set condition codes
An ⇒ SP; (SP) ⇒ An, SP + 4 ⇒ SP
1. Privileged instruction.
2. Two LPSTOP modes are supported. The first LPSTOP mode is the normal LPSTOP in which the system clock
on the chip is stopped, shutting down all IMB modules with the exception of some parts of the SIML and
CLKOUT. The second LPSTOP mode causes the system clock to be stopped only at the CPU32L, when the
LPSTOP instruction is executed by the CPU32L. As with the normal LPSTOP operation, the CPU32L can be
restarted by an interrupt, a trace, or a reset exception.
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4.7 Background Debugging Mode
The background debugger on the CPU32L is implemented in CPU microcode. The background debugging commands are summarized in Table 34.
Table 34 Background Debugging Mode Commands
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Command
Mnemonic
Description
Read D/A Register
RDREG/RAREG
Read the selected address or data register and return
the results through the serial interface.
Write D/A Register
WDREG/WAREG
The data operand is written to the specified address or
data register.
Read System Register
RSREG
The specified system control register is read. All registers that can be read in supervisor mode can be read in
background mode.
Write System Register
WSREG
The operand data is written into the specified system
control register.
READ
Read the sized data at the memory location specified
by the long-word address. The source function code
register (SFC) determines the address space accessed.
WRITE
Write the operand data to the memory location specified by the long-word address. The destination function
code (DFC) register determines the address space accessed.
DUMP
Used in conjunction with the READ command to dump
large blocks of memory. An initial READ is executed to
set up the starting address of the block and retrieve the
first result. Subsequent operands are retrieved with the
DUMP command.
Fill Memory Block
FILL
Used in conjunction with the WRITE command to fill
large blocks of memory. Initially, a WRITE is executed
to set up the starting address of the block and supply
the first operand. The FILL command writes subsequent operands.
Resume Execution
GO
The pipe is flushed and refilled before resuming instruction execution at the current PC.
Patch User Code
CALL
Current program counter is stacked at the location of
the current stack pointer. Instruction execution begins
at user patch code.
Reset Peripherals
RST
Asserts RESET for 512 clock cycles. The CPU is not
reset by this command. Synonymous with the CPU RESET instruction.
No Operation
NOP
NOP performs no operation and can be used as a null
command.
Read Memory Location
Write Memory Location
Dump Memory Block
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5 Queued Serial Module
The QSM contains two serial interfaces, the queued serial peripheral interface (QSPI) and the serial
communication interface (SCI). Figure 14 shows the QSM block diagram.
MISO/PQS0
MOSI/PQS1
SCK/PQS2
PCS0/SS/PQS3
PCS1/PQS4
PCS2/PQS5
PCS3/PQS6
INTERFACE
LOGIC
PORT QS
IMB
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QSPI
TXD/PQS7
SCI
RXD
QSM BLOCK
Figure 14 QSM Block Diagram
5.1 Overview
The QSPI provides easy peripheral expansion or interprocessor communication through a full-duplex,
synchronous, three-line bus: data in, data out, and a serial clock. Four programmable peripheral chipselect pins provide addressability for up to 16 peripheral devices. A self-contained RAM queue allows
up to 16 serial transfers of 8 to 16 bits each, or transmission of a 256-bit data stream without CPU intervention. A special wraparound mode supports continuous sampling of a serial peripheral, with automatic QSPI RAM updating, which makes the interface to A/D converters more efficient.
The SCI provides a standard non-return to zero (NRZ) mark/space format. It operates in either full- or
half-duplex mode. There are separate transmitter and receiver enable bits and dual data buffers. A
modulus-type baud rate generator provides rates from 55 to 451 kbaud with a 14.44-MHz system clock.
Word length of either eight or nine bits is software selectable. Optional parity generation and detection
provide either even or odd parity check capability. Advanced error detection circuitry catches glitches
of up to 1/16 of a bit time in duration. Wakeup functions allow the CPU to run uninterrupted until meaningful data is available.
Table 35 shows the address map of the QSM.
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5.2 Address Map
The “Access” column in the QSM address map in Table 35 indicates which registers are accessible only
at the supervisor privilege level and which can be assigned to either the supervisor or user privilege
level, according to the value of the SUPV bit in the QSMCR.
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Table 35 QSM Address Map
Access
Address
S
$YFFC001
15
QSM Module Configuration Register (QSMCR)
8 7
S
$YFFC02
QSM Test Register (QTEST)
S
$YFFC04
S/U
$YFFC06
Not Used
S/U
$YFFC08
SCI Control 0 Register (SCCR0)
S/U
$YFFC0A
SCI Control 1 Register (SCCR1)
S/U
$YFFC0C
SCI Status Register (SCSR)
S/U
$YFFC0E
SCI Data Register (SCDR)
S/U
$YFFC10
Not Used
S/U
$YFFC12
Not Used
S/U
$YFFC14
Not Used
PQS Data Register (PORTQS)
S/U
$YFFC16
PQS Pin Assignment Register
(PQSPAR)
PQS Data Direction Register
(DDRQS)
S/U
$YFFC18
SPI Control Register 0 (SPCR0)
S/U
$YFFC1A
SPI Control Register 1 (SPCR1)
S/U
$YFFC1C
SPI Control Register 2 (SPCR2)
S/U
$YFFC1E
S/U
$YFFC20 –
$YFFCFF
Not Used
S/U
$YFFD00 –
$YFFD1F
Receive RAM (RR[0:F])
S/U
$YFFD20 –
$YFFD3F
Transmit RAM (TR[0:F])
S/U
$YFFD40 –
$YFFD4F
Command RAM (CR[0:F])
QSM Interrupt Level Register
(QILR)
0
QSM Interrupt Vector Register
(QIVR)
SPI Control Register 3 (SPCR3)
SPI Status Register (SPSR)
NOTES:
1. Y = M111, where M is the logic state of the MM bit in the SIMLCR.
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5.3 Pin Function
Table 36 is a summary of the functions of the QSM pins when they are not configured for general-purpose I/O. The QSM data direction register (DDRQS) designates each pin except RXD as an input or
output.
Table 36 QSM Pin Functions
Pin
Mode
Pin Function
MISO
Master
Serial data input to QSPI
Slave
Serial data output from QSPI
MOSI
Master
Serial data output from QSPI
Slave
Serial data input to QSPI
SCK
Master
Clock output from QSPI
Slave
Clock input to QSPI
Master
Input: Assertion causes mode fault
Output: Selects peripherals
Slave
Input: Selects the QSPI
Master
Output: Selects peripherals
Slave
None
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QSPI Pins
PCS0/SS
PCS[3:1]
SCI Pins
TXD
Transmit
Serial data output from SCI
RXD
Receive
Serial data input to SCI
5.4 QSM Registers
QSM registers are divided into four categories: QSM global registers, QSM pin control registers, QSPI
submodule registers, and SCI submodule registers. The QSPI and SCI registers are defined in separate
sections below. Writes to unimplemented register bits have no meaning or effect, and reads from unimplemented bits always return a logic zero value.
The module mapping bit of the SIML configuration register (SIMLCR) defines the most significant bit
(ADDR23) of the address, shown in each register figure as Y (Y = $7 or $F). This bit, concatenated with
the rest of the address given, forms the absolute address of each register. Refer to the SIML section of
this technical summary for more information about how the state of MM affects the system.
5.4.1 Global Registers
The QSM global registers contain system parameters used by both the QSPI and the SCI submodules.
These registers contain the bits and fields used to configure the QSM.
QSMCR — QSM Configuration Register
$YFFC00
15
14
13
12
11
10
9
8
7
6
5
4
STOP
FRZ1
FRZ0
0
0
0
0
0
SUPV
0
0
0
0
0
0
0
0
0
0
0
0
0
3
2
1
0
0
0
IARB
RESET:
0
0
0
0
The QSMCR contains parameters for the QSM/CPU/intermodule bus (IMB) interface.
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STOP — Stop Enable
0 = Normal QSM clock operation
1 = QSM clock operation stopped
STOP places the QSM in a low-power state by disabling the system clock in most parts of the module.
The QSMCR is the only register guaranteed to be readable while STOP is asserted. The QSPI RAM is
not readable. However, writes to RAM or any register are guaranteed to be valid while STOP is asserted. STOP can be negated by the CPU and by reset.
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The system software must stop each submodule before asserting STOP to avoid complications at restart and to avoid data corruption. The SCI submodule receiver and transmitter should be disabled, and
the operation should be verified for completion before asserting STOP. The QSPI submodule should be
stopped by asserting the HALT bit in SPCR3 and by asserting STOP after the HALTA flag is set.
FRZ1 — Freeze 1
0 = Ignore the FREEZE signal on the IMB
1 = Halt the QSPI (on a transfer boundary)
FRZ1 determines what action is taken by the QSPI when the FREEZE signal of the IMB is asserted.
FREEZE is asserted whenever the CPU enters the background mode.
FRZ0 — Freeze 0
Reserved
Bits [12:8] — Not Implemented
SUPV — Supervisor/Unrestricted
0 = User access
1 = Supervisor access
SUPV defines the assignable QSM registers as either supervisor-only data space or unrestricted data
space.
IARB — Interrupt Arbitration Identification Number
The IARB field is used to arbitrate between simultaneous interrupt requests of the same priority. Each
module that can generate interrupt requests must be assigned a unique, non-zero IARB field value.
Refer to 3.9 Interrupts for more information.
QTEST — QSM Test Register
$YFFC02
QTEST is used during factory testing of the QSM. Accesses to QTEST must be made while the MCU
is in test mode.
QILR — QSM Interrupt Levels Register
15
14
0
0
13
12
11
10
ILQSPI
$YFFC04
9
8
ILSCI
7
6
5
4
3
2
1
0
QIVR
RESET:
0
0
0
0
0
0
0
0
QILR determines the priority level of interrupts requested by the QSM and the vector used when an interrupt is acknowledged.
ILQSPI — Interrupt Level for QSPI
ILQSPI determines the priority of QSPI interrupts. This field must be given a value between $0 (interrupts disabled) to $7 (highest priority).
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ILSCI — Interrupt Level of SCI
ILSCI determines the priority of SCI interrupts. This field must be given a value between $0 (interrupts
disabled) to $7 (highest priority).
If ILQSPI and ILSCI are the same nonzero value, and both submodules simultaneously request interrupt service, QSPI has priority.
QIVR — QSM Interrupt Vector Register
15
14
13
12
11
10
$YFFC05
9
8
7
6
5
4
QILR
3
2
1
0
1
1
1
1
INTV
RESET:
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0
0
0
0
At reset, QIVR is initialized to $0F, which corresponds to the uninitialized interrupt vector in the exception table. This vector is selected until QIVR is written. A user-defined vector ($40–$FF) should be written to QIVR during QSM initialization.
After initialization, QIVR determines which two vectors in the exception vector table are to be used for
QSM interrupts. The QSPI and SCI submodules have separate interrupt vectors adjacent to each other.
Both submodules use the same interrupt vector with the least significant bit (LSB) determined by the
submodule causing the interrupt.
The value of INTV0 used during an interrupt-acknowledge cycle is supplied by the QSM. During an interrupt-acknowledge cycle, INTV[7:1] are driven on DATA[7:1] IMB lines. DATA0 is negated for an SCI
interrupt and asserted for a QSPI interrupt. Writes to INTV0 have no meaning or effect. Reads of INTV0
return a value of one.
5.4.2 Pin Control Registers
The QSM uses nine pins, eight of which form a parallel port (PORTQS) on the MCU. Although these
pins are used by the serial subsystems, any pin can alternately be assigned as general-purpose I/O on
a pin-by-pin basis.
Pins used for general-purpose I/O must not be assigned to the QSPI by register PQSPAR. To avoid
driving incorrect data, the first byte to be output must be written before DDRQS is configured. DDRQS
must then be written to determine the direction of data flow and to output the value contained in register
PORTQS. Subsequent data for output is written to PORTQS.
PORTQS — Port QS Data Register
15
14
13
12
11
RESERVED
10
$YFFC14
9
8
7
6
5
4
3
2
1
0
PQS7
PQS6
PQS5
PQS4
PQS3
PQS2
PQS1
PQS0
0
0
0
0
0
0
0
0
RESET:
PORTQS latches I/O data. Writes drive pins defined as outputs. Reads return data present on the pins.
To avoid driving undefined data, first write a byte to PORTQS, then configure DDRQS.
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PQSPAR — PORT QS Pin Assignment Register
DDRQS — PORT QS Data Direction Register
15
0
14
13
12
11
10
PQSPA6 PQSPA5 PQSPA4 PQSPA3
0
9
$YFFC16
$YFFC17
8
7
6
5
4
3
2
1
0
PQSPA1 PQSPA0 DDQS7 DDQS6 DDQS5 DDQS4 DDQS3 DDQS2 DDQS1 DDQS0
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Clearing a bit in the PQSPAR assigns the corresponding pin to general-purpose I/O; setting a bit assigns the pin to the QSPI. The PQSPAR does not affect operation of the SCI. Table 37 displays PQSPAR pin assignments.
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Table 37 PQSPAR Pin Assignments
PQSPAR Field
PQSPAR Bit
Pin Function
PQSPA0
0
PQS0
1
MISO
0
PQS1
PQSPA1
PQSPA2
PQSPA3
PQSPA4
PQSPA5
PQSPA6
PQSPA7
1
MOSI
0
PQS21
1
SCK
0
PQS3
1
PCS0/SS
0
PQS4
1
PCS1
0
PQS5
1
PCS2
0
PQS6
1
PCS3
0
PQS72
1
TXD
NOTES:
1. PQS2 is a digital I/O pin unless the SPI is enabled (SPE in SPCR1 set), in which case it becomes SPI serial clock SCK.
2. PQS7 is a digital I/O pin unless the SCI transmitter is enabled (TE in SCCR1 = 1), in which
case it becomes SCI serial output TXD.
DDRQS determines whether pins are inputs or outputs. Clearing a bit makes the corresponding pin an
input; setting a bit makes the pin an output. DDRQS affects both QSPI function and I/O function. Table
38 shows the effect of DDRQS on QSM pin functions.
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Table 38 Effect of DDRQS on QSM Pin Function
QSM Pin
Mode
DDRQS Bit
Bit State
Pin Function
MISO
Master
DDQ0
0
Serial data input to QSPI
Slave
MOSI
Master
DDQ1
Slave
1
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SCK
Master
DDQ2
Slave
PCS0/SS
Master
DDQ3
Slave
PCS[3:1]
Master
DDQ[4:6]
Slave
1
Disables data input
0
Disables data output
1
Serial data output from QSPI
0
Disables data output
1
Serial data output from QSPI
0
Serial data input to QSPI
1
Disables data input
0
Disables clock output
1
Clock output from QSPI
0
Clock input to QSPI
1
Disables clock Input
0
Assertion causes mode fault
1
Chip-select output
0
QSPI slave select input
1
Disables select input
0
Disables chip-select output
1
Chip-select output
0
Inactive
1
Inactive
2
TXD
Transmit
DDQ7
X
Serial data output from SCI
RXD
Receive
None
NA
Serial data input to SCI
NOTES:
1. PQS2 is a digital I/O pin unless the SPI is enabled (SPE in SPCR1 set), in which case it becomes
SPI serial clock SCK.
2. PQS7 is a digital I/O pin unless the SCI transmitter is enabled (TE in SCCR1 = 1), in which case
it becomes SCI serial output TXD.
DDRQS determines the direction of the TXD pin only when the SCI transmitter is disabled. When the
SCI transmitter is enabled, the TXD pin is an output.
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5.5 QSPI Submodule
The QSPI submodule communicates with external devices through a synchronous serial bus. The QSPI
is fully compatible with the serial peripheral interface (SPI) systems found on other Motorola products.
Figure 15 shows a block diagram of the QSPI.
QUEUE CONTROL
BLOCK
QUEUE
POINTER
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COMPARATOR
4
A
D
D
R
E
S
S
DONE
4
END QUEUE
POINTER
80-BYTE
QSPI RAM
R
E
G
I
S
T
E
R
CONTROL
LOGIC
STATUS
REGISTER
CONTROL
REGISTERS
4
DELAY
COUNTER
CHIP SELECT
4
COMMAND
MSB
M
S
LSB
8/16-BIT SHIFT REGISTER
PROGRAMMABLE
LOGIC ARRAY
MOSI
Rx/Tx DATA REGISTER
M
S
MISO
PCS0/SS
2
PCS[2:1]
BAUD RATE
GENERATOR
SCK
QSPI BLOCK
Figure 15 QSPI Block Diagram
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5.5.1 QSPI Pins
Seven pins are associated with the QSPI. When not needed for a QSPI function, they can be configured
as general-purpose I/O pins. The PCS0/SS pin can function as a peripheral chip select output, slave
select input, or general-purpose I/O. Refer to Table 39 for QSPI input and output pins and their functions.
Table 39 QSPI Pins
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Pin Name(s)
Mnemonic(s)
Mode
Function
Master In Slave Out
MISO
Master
Slave
Serial data input to QSPI
Serial data output from QSPI
Master Out Slave In
MOSI
Master
Slave
Serial data output from QSPI
Serial data input to QSPI
Serial Clock
SCK
Master
Slave
Clock output from QSPI
Clock input to QSPI
Peripheral Chip Selects
PCS[3:1]
Master
Select peripherals
Peripheral Chip Select
Slave Select
PCS0
SS
Master
Master
Slave
Selects peripheral
Causes mode fault
Initiates serial transfer
5.5.2 QSPI Registers
The programmer's model for the QSPI submodule consists of the QSM global and pin control registers,
four QSPI control registers, one status register, and the 80-byte QSPI RAM.
The CPU can read and write to registers and RAM. The four control registers must be initialized before
the QSPI is enabled to ensure defined operation. SPCR1 should be written last because it contains
QSPI enable bit SPE. Asserting this bit starts the QSPI. The QSPI control registers are reset to a defined state and can then be changed by the CPU. Reset values are shown below each register.
Table 40 shows a memory map of the QSPI.
Table 40 QSPI Memory Map
Address
Name
Usage
$YFFC18
SPCR0
QSPI control register 0
$YFFC1A
SPCR1
QSPI control register 1
$YFFC1C
SPCR2
QSPI control register 2
$YFFC1E
SPCR3
QSPI control register 3
$YFFC1F
SPSR
QSPI status register
$YFFD00
RR[0:F]
QSPI receive data (16 words)
$YFFD20
TR[0:F]
QSPI transmit data (16 words)
$YFFD40
CR[0:F]
QSPI command control (8 words)
Writing a different value into any control register except SPCR2 while the QSPI is enabled disrupts operation. SPCR2 is buffered to prevent disruption of the current serial transfer. After completion of the
current serial transfer, the new SPCR2 values become effective.
Writing the same value into any control register except SPCR2 while the QSPI is enabled has no effect
on QSPI operation. Rewriting NEWQP[3:0] in SPCR2 causes execution to restart at the designated
location.
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SPCR0 — QSPI Control Register 0
15
14
MSTR
WOMQ
13
12
11
$YFFC18
10
BITS[3:0]
9
8
CPOL
CPHA
0
1
7
6
5
4
3
2
1
0
1
0
0
SPBR[7:0]
RESET:
0
0
0
0
0
0
0
0
0
0
0
SPCR0 contains parameters for configuring the QSPI before it is enabled. The CPU can read and write
this register. The QSM has read-only access.
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MSTR — Master/Slave Mode Select
0 = QSPI is a slave device and only responds to externally generated serial data.
1 = QSPI is system master and can initiate transmission to external SPI devices.
MSTR configures the QSPI for either master or slave mode operation. This bit is cleared on reset and
may only be written by the CPU.
WOMQ — Wired-OR Mode for QSPI Pins
0 = Outputs have normal MOS drivers.
1 = Pins designated for output by DDRQS have open-drain drivers.
WOMQ allows the wired-OR function to be used on QSPI pins, regardless of whether they are used as
general-purpose outputs or as QSPI outputs. WOMQ affects the QSPI pins regardless of whether the
QSPI is enabled or disabled.
BITS[3:0] — Bits Per Transfer
In master mode, when BITSE in a command is set, the BITS[3:0] field determines the number of data
bits transferred. When BITSE is cleared, eight bits are transferred. Reserved values default to eight bits.
In slave mode, the command RAM is not used and the setting of BITSE has no effect on QSPI transfers.
Instead, the BITS[3:0] field determines the number of bits the QSPI will receive during each transfer before storing the received data. Table 41 shows the number of bits per transfer.
Table 41 Bits Per Transfer
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BITS[3:0]
Bits Per Transfer
0000
16
0001
Reserved
0010
Reserved
0011
Reserved
0100
Reserved
0101
Reserved
0110
Reserved
0111
Reserved
1000
8
1001
9
1010
10
1011
11
1100
12
1101
13
1110
14
1111
15
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CPOL — Clock Polarity
0 = The inactive state value of SCK is logic level zero.
1 = The inactive state value of SCK is logic level one.
CPOL is used to determine the inactive state value of the serial clock (SCK). It is used with CPHA to
produce a desired clock/data relationship between master and slave devices.
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CPHA — Clock Phase
0 = Data is captured on the leading edge of SCK and changed on the following edge of SCK.
1 = Data is changed on the leading edge of SCK and captured on the following edge of SCK.
CPHA determines which edge of SCK causes data to change and which edge causes data to be captured. CPHA is used with CPOL to produce a desired clock/data relationship between master and slave
devices. CPHA is set at reset.
SPBR[7:0] — Serial Clock Baud Rate
The QSPI uses a modulus counter to derive SCK baud rate from the MCU system clock. Baud rate is
selected by writing a value from 2 to 255 into the SPBR[7:0] field. The following equation determines
the SCK baud rate:
System Clock
SCK Baud Rate = ------------------------------------2 × SPBR[7:0]
or
System Clock
SPBR[7:0] = -------------------------------------------------------------------------2 × SCK Baud Rate Desired
Giving SPBR[7:0] a value of zero or one disables the baud rate generator. SCK is disabled and assumes its inactive state value. No serial transfers occur. At reset, baud rate is initialized to one eighth
of the system clock frequency.
SPRC1 — QSPI Control Register 1
15
14
13
12
SPE
11
$YFFC1A
10
9
8
7
6
5
4
DSCKL[6:0]
3
2
1
0
0
1
0
0
DTL[7:0]
RESET:
0
0
0
0
0
1
0
0
0
0
0
0
SPCR1 contains parameters for configuring the QSPI before it is enabled. The CPU can read and write
this register, but the QSM has read access only, except for SPE, which is automatically cleared by the
QSPI after completing all serial transfers, or when a mode fault occurs.
SPE — QSPI Enable
0 = QSPI is disabled. QSPI pins can be used for general-purpose I/O.
1 = QSPI is enabled. Pins allocated by PQSPAR are controlled by the QSPI.
DSCKL[6:0] — Delay before SCK
When the DSCK bit in command RAM is set, this field determines the length of delay from PCS valid to
SCK transition. PCS can be any of the four peripheral chip-select pins. The following equation determines the actual delay before SCK:
DSCKL[6:0]
PCS to SCK Delay = -----------------------------------System Clock
where DSCKL[6:0] equals {1, 2, 3,..., 127}.
When the DSCK value of a queue entry equals zero, then DSCKL[6:0] is not used. Instead, the PCS
valid-to-SCK transition is one-half SCK period.
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DTL[7:0] — Length of Delay after Transfer
When the DT bit in command RAM is set, this field determines the length of delay after serial transfer.
The following equation is used to calculate the delay:
32 × DTL[7:0]
Delay after Transfer = -----------------------------------System Clock
where DTL equals {1, 2, 3,..., 255}.
A zero value for DTL[7:0] causes a delay-after-transfer value of 8192/System Clock.
If DT equals zero, a standard delay is inserted.
17
Standard Delay after Transfer = -----------------------------------System Clock
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Delay after transfer can be used to provide a peripheral deselect interval. A delay can also be inserted
between consecutive transfers to allow serial A/D converters to complete conversion.
SPCR2 — QSPI Control Register 2
15
14
13
12
SPIFIE
WREN
WRTO
0
0
0
11
$YFFC1C
10
9
8
ENDQP[3:0]
7
6
5
4
0
0
0
0
0
0
0
0
3
2
1
0
NEWQP[3:0]
RESET:
0
0
0
0
0
0
0
0
0
0
SPCR2 contains QSPI configuration parameters. The CPU can read and write this register; the QSM
has read access only. Writes to SPCR2 are buffered. A write to SPCR2 that changes a bit value while
the QSPI is operating is ineffective on the current serial transfer, but becomes effective on the next serial transfer. Reads of SPCR2 return the current value of the register, not of the buffer.
SPIFIE — SPI Finished Interrupt Enable
0 = QSPI interrupts disabled
1 = QSPI interrupts enabled
SPIFIE enables the QSPI to generate a CPU interrupt upon assertion of the status flag SPIF.
WREN — Wrap Enable
0 = Wraparound mode disabled
1 = Wraparound mode enabled
WREN enables or disables wraparound mode.
WRTO — Wrap To
When wraparound mode is enabled, after the end of queue has been reached, WRTO determines
which address the QSPI executes.
Bit 12 — Not Implemented
ENDQP[3:0] — Ending Queue Pointer
This field contains the last QSPI queue address.
Bits [7:4] — Not Implemented
NEWQP[3:0] — New Queue Pointer Value
This field contains the first QSPI queue address.
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SPCR3 — QSPI Control Register
$YFFC1E
15
14
13
12
11
10
9
8
0
0
0
0
0
LOOPQ
HMIE
HALT
0
0
0
0
0
0
0
7
6
5
4
3
2
1
0
SPSR
RESET:
0
SPCR3 contains QSPI configuration parameters. The CPU can read and write SPCR3, but the QSM
has read-only access.
Bits [15:11] — Not Implemented
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LOOPQ — QSPI Loop Mode
0 = Feedback path disabled
1 = Feedback path enabled
LOOPQ controls feedback on the data serializer for testing.
HMIE — HALTA and MODF Interrupt Enable
0 = HALTA and MODF interrupts disabled
1 = HALTA and MODF interrupts enabled
HMIE controls CPU interrupts caused by the HALTA status flag or the MODF status flag in SPSR.
HALT — Halt
0 = Halt not enabled
1 = Halt enabled
When HALT is asserted, the QSPI stops on a queue boundary. It is in a defined state from which it can
later be restarted.
SPSR — QSPI Status Register
15
14
13
12
11
SPCR3
$YFFC1F
10
9
8
7
6
5
4
SPIF
MODF
HALTA
0
0
0
0
0
3
2
1
0
CPTQP[3:0]
RESET:
0
0
0
0
SPSR contains QSPI status information. Only the QSPI can assert the bits in this register. The CPU
reads this register to obtain status information and writes it to clear status flags.
SPIF — QSPI Finished Flag
0 = QSPI not finished
1 = QSPI finished
SPIF is set after execution of the command at the address in ENDQP[3:0].
MODF — Mode Fault Flag
0 = Normal operation
1 = Another SPI node requested to become the network SPI master while the QSPI was enabled
in master mode (SS input taken low).
The QSPI asserts MODF when the QSPI is the serial master (MSTR = 1) and the SS input pin is negated by an external driver.
HALTA — Halt Acknowledge Flag
0 = QSPI not halted
1 = QSPI halted
HALTA is asserted when the QSPI halts in response to CPU assertion of HALT.
Bit 4 — Not Implemented
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CPTQP[3:0] — Completed Queue Pointer
CPTQP[3:0] points to the last command executed. It is updated when the current command is complete.
When the first command in a queue is executing, CPTQP[3:0] contains either the reset value ($0) or a
pointer to the last command completed in the previous queue.
5.5.3 QSPI RAM
The QSPI contains an 80-byte block of dual-access static RAM that is used by both the QSPI and the
CPU. The RAM is divided into three segments: receive data, transmit data, and command control data.
Receive data is information received from a serial device external to the MCU. Transmit data is information stored by the CPU for transmission to an external peripheral. Command control data is used to
perform the transfer.
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Figure 16 displays the organization of the RAM.
500
51E
RR0
RR1
RR2
520
TR0
TR1
TR2
540
CR0
CR1
CR2
RECEIVE
RAM
TRANSMIT
RAM
COMMAND
RAM
RRD
RRE
RRF
TRD
TRE
TRF
CRD
CRE
CRF
WORD
53E
WORD
54F
BYTE
QSPI RAM MAP
Figure 16 QSPI RAM
Once the CPU has set up the queue of QSPI commands and enabled the QSPI, the QSPI can operate
independently of the CPU. The QSPI executes all of the commands in its queue, sets a flag indicating
that it is finished, and then either interrupts the CPU or waits for CPU intervention. It is possible to execute a queue of commands repeatedly without CPU intervention.
RR[0:F] — Receive Data RAM
$YFFD00
Data received by the QSPI is stored in this segment. The CPU reads this segment to retrieve data from
the QSPI. Data stored in receive RAM is right-justified. Unused bits in a receive queue entry are set to
zero by the QSPI upon completion of the individual queue entry. The CPU can access the data using
byte, word, or long-word addressing.
The CPTQP[3:0] value in SPSR shows which queue entries have been executed. The CPU uses this
information to determine which locations in receive RAM contain valid data before reading them.
TR[0:F] — Transmit Data RAM
$YFFD20
Data that is to be transmitted by the QSPI is stored in this segment. The CPU usually writes one word
of data into this segment for each queue command to be executed.
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Information to be transmitted must be written to transmit data RAM in a right-justified format. The QSPI
cannot modify information in the transmit data RAM. The QSPI copies the information to its data serializer for transmission. Information remains in transmit RAM until overwritten.
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CR[0:F] — Command RAM
$YFFD40
7
6
5
4
3
2
1
0
CONT
BITSE
DT
DSCK
PCS3
PCS2
PCS1
PCS01
–
–
–
–
–
–
–
–
CONT
BITSE
DT
DSCK
PCS3
PCS2
PCS1
PCS01
COMMAND CONTROL
PERIPHERAL CHIP SELECT
NOTES:
1. The PCS0 bit represents the dual-function PCS0/SS.
Command RAM is used by the QSPI when in master mode. The CPU writes one byte of control information to this segment for each QSPI command to be executed. The QSPI cannot modify information
in command RAM.
Command RAM consists of 16 bytes. Each byte is divided into two fields. The peripheral chip-select
field enables peripherals for transfer. The command control field provides transfer options.
A maximum of 16 commands can be in the queue. Queue execution by the QSPI proceeds from the
address in NEWQP[3:0] through the address in ENDQP[3:0]. (Both of these fields are in SPCR2).
CONT — Continue
0 = Control of chip selects returned to PORTQS after transfer is complete.
1 = Peripheral chip selects remain asserted after transfer is complete.
BITSE — Bits per Transfer Enable
0 = 8 bits
1 = Number of bits set in BITS[3:0] field of SPCR0
DT — Delay after Transfer
The QSPI provides a variable delay at the end of serial transfer to facilitate the interface with peripherals
that have a latency requirement. The delay between transfers is determined by the SPCR1 DTL[6:0]
field.
DSCK — PCS to SCK Delay
0 = PCS valid to SCK transition is one-half SCK.
1 = SPCR1 DSCKL[6:0] field specifies delay from PCS valid to SCK.
PCS[3:0] — Peripheral Chip Select
Use peripheral chip-select bits to select an external device for serial data transfer. More than one peripheral chip select can be activated at a time, and more than one peripheral chip can be connected to
each PCS pin, provided that proper fanout is observed.
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5.5.4 Operating Modes
The QSPI operates in either master or slave mode. Master mode is used when the MCU originates data
transfers. Slave mode is used when an external device initiates serial transfers to the MCU through the
QSPI. Switching between the modes is controlled by MSTR in SPCR0. Before entering either mode,
appropriate QSM and QSPI registers must be properly initialized.
In master mode, the QSPI executes a queue of commands defined by control bits in each command
RAM queue entry. Chip-select pins are activated, data is transmitted from transmit RAM and received
into receive RAM.
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In slave mode, operation proceeds in response to SS pin activation by an external bus master. Operation is similar to master mode, but no peripheral chip selects are generated, and the number of bits
transferred is controlled in a different manner. When the QSPI is selected, it automatically executes the
next queue transfer to exchange data with the external device correctly.
Although the QSPI inherently supports multi-master operation, no special arbitration mechanism is provided. A mode fault flag (MODF) indicates a request for SPI master arbitration. System software must
provide arbitration. Note that unlike previous SPI systems, MSTR is not cleared by a mode fault being
set, nor are the QSPI pin output drivers disabled. The QSPI and associated output drivers must be disabled by clearing SPE in SPCR1.
5.6 SCI Submodule
The SCI submodule is used to communicate with external devices through an asynchronous serial bus.
The SCI is fully compatible with the SCI systems found on other Motorola MCUs, such as the M68HC11
and M68HC05 Families.
5.6.1 SCI Pins
There are two unidirectional pins associated with the SCI. The SCI controls the transmit data (TXD) pin
when enabled, whereas the receive data (RXD) pin remains a dedicated input pin to the SCI. TXD is
available as a general-purpose I/O pin when the SCI transmitter is disabled. When used for I/O, TXD
can be configured either as input or output, as determined by QSM register DDRQS.
Table 42 shows SCI pins and their functions.
Table 42 SCI Pins
Pin Names
Mnemonics
Mode
Function
Receive data
RXD
Receiver disabled
Receiver enabled
Not used
Serial data input to SCI
Transmit data
TXD
Transmitter disabled
Transmitter enabled
General-purpose I/O
Serial data output from SCI
5.6.2 SCI Registers
The SCI programming model includes QSM global and pin control registers, and four SCI registers.
There are two SCI control registers, one status register, and one data register. All registers can be read
or written at any time by the CPU.
Changing the value of SCI control bits during a transfer operation may disrupt operation. Before changing register values, allow the transmitter to complete the current transfer, then disable the receiver and
transmitter. Status flags in the SCSR may be cleared at any time.
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SCCR0 — SCI Control Register 0
15
14
13
0
0
0
0
0
12
$YFFC08
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
1
0
0
SCBR[12:0]
RESET:
0
0
0
0
0
0
0
0
SCCR0 contains a baud rate selection parameter. Baud rate must be set before the SCI is enabled. The
CPU can read and write this register at any time.
Bits [15:13] — Not Implemented
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SCBR[12:0] — Baud Rate
SCI baud rate is programmed by writing a 13-bit value to BR. The baud rate is derived from the MCU
system clock by a modulus counter.
The SCI receiver operates asynchronously. An internal clock is necessary to synchronize with an incoming data stream. The SCI baud rate generator produces a receiver sampling clock with a frequency
16 times that of the expected baud rate of the incoming data. The SCI determines the position of bit
boundaries from transitions within the received waveform, and adjusts sampling points to the proper positions within the bit period. Receiver sampling rate is always 16 times the frequency of the SCI baud
rate, which is calculated as follows:
System Clock
SCI Baud Rate = -----------------------------------------------( 32 ) ( SCBR[12:0] )
or
System Clock
SCBR[12:0] = --------------------------------------------------------------------------32 × SCI Baud Rate Desired
where SCBR[12:0] is in the range {1, 2, 3, …, 8191}
Writing a value of zero to SCBR[12:0] disables the baud rate generator.
Table 43 lists the SCBR[12:0] settings for standard and maximum baud rates using a 14.44 MHz system clock.
Table 43 SCI Baud Rates
Nominal Baud Rate
MC68CK338
MC68CK338TS/D
Actual Rate with
14.44 MHz Clock
SCBR[12:0] Value
64
64.0
$1B8B
110
110.0
$1006
300
300.0
$05E0
600
600.1
$02F0
1200
1200.1
$0178
2400
2400.3
$00BC
4800
4800.5
$005E
9600
9601.1
$002F
19200
18802.1
$0018
38400
37604.2
$000C
76800
75208.3
$0006
Maximum rate
451250.0
$0001
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SCCR1 — SCI Control Register 1
15
0
14
13
LOOPS WOMS
$YFFC0A
12
11
10
9
8
7
6
5
4
3
2
1
0
ILT
PT
PE
M
WAKE
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0
0
0
0
0
0
0
0
0
0
0
0
0
RESET:
0
0
0
SCCR1 contains SCI configuration parameters. The CPU can read and write this register at any time.
The SCI can modify RWU in some circumstances. In general, interrupts enabled by these control bits
are cleared by reading SCSR, then reading (for receiver status bits) or writing (for transmitter status bits)
SCDR.
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Bit 15 — Not Implemented
LOOPS — Loop Mode
0 = Normal SCI operation, no looping, feedback path disabled
1 = Test SCI operation, looping, feedback path enabled
LOOPS controls a feedback path on the data serial shifter. When loop mode is enabled, SCI transmitter
output is fed back into the receive serial shifter. TXD is asserted (idle line). Both transmitter and receiver
must be enabled before entering loop mode.
WOMS — Wired-OR Mode for SCI Pins
0 = If configured as an output, TXD is a normal CMOS output.
1 = If configured as an output, TXD is an open-drain output.
WOMS determines whether the TXD pin is an open-drain output or a normal CMOS output. This bit is
used only when TXD is an output. If TXD is used as a general-purpose input pin, WOMS has no effect.
ILT — Idle-Line Detect Type
0 = Short idle-line detect (start count on first one)
1 = Long idle-line detect (start count on first one after stop bit(s))
PT — Parity Type
0 = Even parity
1 = Odd parity
When parity is enabled, PT determines whether parity is even or odd for both the receiver and the transmitter.
PE — Parity Enable
0 = SCI parity disabled
1 = SCI parity enabled
PE determines whether parity is enabled or disabled for both the receiver and the transmitter. If the received parity bit is not correct, the SCI sets the PF error flag in SCSR.
When PE is set, the most significant bit (MSB) of the data field is used for the parity function, which results in either seven or eight bits of user data, depending on the condition of M bit. Table 44 lists the
available choices.
Table 44 Parity Enable Data Bit Selection
MOTOROLA
74
M
PE
Result
0
0
8 data bits
0
1
7 data bits, 1 parity bit
1
0
9 data bits
1
1
8 data bits, 1 parity bit
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M — Mode Select
0 = SCI frame: one start bit, eight data bits, one stop bit (10 bits total)
1 = SCI frame: one start bit, nine data bits, one stop bit (11 bits total)
WAKE — Wakeup by Address Mark
0 = SCI receiver awakened by idle-line detection
1 = SCI receiver awakened by address mark (last bit set)
TIE — Transmit Interrupt Enable
0 = SCI TDRE interrupts inhibited
1 = SCI TDRE interrupts enabled
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TCIE — Transmit Complete Interrupt Enable
0 = SCI TC interrupts inhibited
1 = SCI TC interrupts enabled
RIE — Receiver Interrupt Enable
0 = SCI RDRF interrupt inhibited
1 = SCI RDRF interrupt enabled
ILIE — Idle-Line Interrupt Enable
0 = SCI IDLE interrupts inhibited
1 = SCI IDLE interrupts enabled
TE — Transmitter Enable
0 = SCI transmitter disabled (TXD pin may be used as I/O)
1 = SCI transmitter enabled (TXD pin dedicated to SCI transmitter)
The transmitter retains control of the TXD pin until completion of any character transfer that was in
progress when TE is cleared.
RE — Receiver Enable
0 = SCI receiver disabled (status bits inhibited)
1 = SCI receiver enabled
RWU — Receiver Wakeup
0 = Normal receiver operation (received data recognized)
1 = Wakeup mode enabled (received data ignored until awakened)
Setting RWU enables the wakeup function, which allows the SCI to ignore received data until awakened
by either an idle line or address mark (as determined by WAKE). When in wakeup mode, the receiver
status flags are not set, and interrupts are inhibited. This bit is cleared automatically (returned to normal
mode) when the receiver is awakened.
SBK — Send Break
0 = Normal operation
1 = Break frame(s) transmitted after completion of current frame
SBK provides the ability to transmit a break code from the SCI. If the SCI is transmitting when SBK is
set, it will transmit continuous frames of zeros after it completes the current frame, until SBK is cleared.
If SBK is toggled (one to zero in less than one frame interval), the transmitter sends only one or two
break frames before reverting to idle line or beginning to send data.
SCSR — SCI Status Register
15
14
13
12
NOT USED
$YFFC0C
11
10
9
8
7
6
5
4
3
2
1
0
TDRE
TC
RDRF
RAF
IDLE
OR
NF
FE
PF
1
1
0
0
0
0
0
0
0
RESET:
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SCSR contains flags that show SCI operational conditions. These flags can be cleared either by hardware or by a special acknowledgment sequence. The sequence consists of SCSR read with flags set,
followed by SCDR read (write in the case of TDRE and TC). A long-word read can consecutively access
both SCSR and SCDR. This action clears receive status flag bits that were set at the time of the read,
but does not clear TDRE or TC flags.
If an internal SCI signal for setting a status bit comes after the CPU has read the asserted status bits,
but before the CPU has written or read register SCDR, the newly set status bit is not cleared. SCSR
must be read again with the bit set. Also, SCDR must be written or read before the status bit is cleared.
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Reading either byte of SCSR causes all 16 bits to be accessed. Any status bit already set in either byte
will be cleared on a subsequent read or write of register SCDR.
TDRE — Transmit Data Register Empty Flag
0 = Register TDR still contains data to be sent to the transmit serial shifter.
1 = A new character can now be written to the transmit data register.
TDRE is set when the byte in the transmit data register is transferred to the transmit serial shifter. If
TDRE is zero, transfer has not occurred and a write to the transmit data register will overwrite the previous value. New data is not transmitted if the transmit data register is written without first clearing
TDRE.
TC — Transmit Complete Flag
0 = SCI transmitter is busy
1 = SCI transmitter is idle
TC is set when the transmitter finishes shifting out all data, queued preambles (mark/idle line), or
queued breaks (logic zero). The interrupt can be cleared by reading SCSR when TC is set and then by
writing the transmit data register of SCDR.
RDRF — Receive Data Register Full Flag
0 = Receive data register is empty or contains previously read data.
1 = Receive data register contains new data.
RDRF is set when the content of the receive serial shifter is transferred to the receive data register. If
one or more errors are detected in the received word, flag(s) NF, FE, and/or PF are set within the same
clock cycle.
RAF — Receiver Active Flag
0 = SCI receiver is idle
1 = SCI receiver is busy
RAF indicates whether the SCI receiver is busy. It is set when the receiver detects a possible start bit
and is cleared when the chosen type of idle line is detected. RAF can be used to reduce collisions in
systems with multiple masters.
IDLE — Idle-Line Detected Flag
0 = SCI receiver did not detect an idle-line condition.
1 = SCI receiver detected an idle-line condition.
IDLE is disabled when RWU in SCCR1 is set. IDLE is set when the SCI receiver detects the idle-line
condition specified by ILT in SCCR1. If cleared, IDLE will not set again until after RDRF is set. RDRF
is set when a break is received, so that a subsequent idle line can be detected.
OR — Overrun Error Flag
0 = RDRF is cleared before new data arrives.
1 = RDRF is not cleared before new data arrives.
OR is set when a new byte is ready to be transferred from the receive serial shifter to the receive data
register, and RDRF is still set. Data transfer is inhibited until OR is cleared. Previous data in receive
data register remains valid, but data received during overrun condition (including the byte that set OR)
is lost.
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NF — Noise Error Flag
0 = No noise detected on the received data
1 = Noise occurred on the received data
NF is set when the SCI receiver detects noise on a valid start bit, on any data bit, or on a stop bit. It is
not set by noise on the idle line or on invalid start bits. Each bit is sampled three times. If none of the
three samples are the same logic level, the majority value is used for the received data value, and NF
is set. NF is not set until an entire frame is received and RDRF is set.
Freescale Semiconductor, Inc...
FE — Framing Error Flag
0 = No framing error on the received data.
1 = Framing error or break occurred on the received data.
FE is set when the SCI receiver detects a zero where a stop bit was to have occurred. FE is not set until
the entire frame is received and RDRF is set. A break can also cause FE to be set. It is possible to miss
a framing error if RXD happens to be at logic level one at the time the stop bit is expected.
PF — Parity Error Flag
0 = No parity error on the received data
1 = Parity error occurred on the received data
PF is set when the SCI receiver detects a parity error. PF is not set until the entire frame is received and
RDRF is set.
SCDR — SCI Data Register
$YFFC0E
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
R8/T8
R7/T7
R6/T6
R5/T5
R4/T4
R3/T3
R2/T2
R1/T1
R0/T0
0
0
0
0
0
0
U
U
U
U
U
U
U
U
U
RESET:
0
SCDR contains two data registers at the same address. The receive data register is a read-only register
that contains data received by the SCI. The data comes into the receive serial shifter and is transferred
to the receive data register. The transmit data register is a write-only register that contains data to be
transmitted. The data is first written to the transmit data register, then transferred to the transmit serial
shifter, where additional format bits are added before transmission. R[7:0]/T[7:0] contain either the first
eight data bits received when SCDR is read, or the first eight data bits to be transmitted when SCDR is
written. R8/T8 are used when the SCI is configured for 9-bit operation. When it is configured for 8-bit
operation, they have no meaning or effect.
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6 Configurable Timer Module 6
The configurable timer module 6 (CTM6) belongs to a family of timer modules for the Motorola Modular
Microcontroller Family. The timer architecture is modular relative to the number of time bases (counter
submodules) and channels (action submodules or timer I/O pins) that are included.
The CTM6 consists of several submodules which are located on either side of the CTM6 internal submodule bus (SMB). All data and control signals within the CTM6 are passed over this bus. The SMB is
connected to the outside world via the bus interface unit submodule (BIUSM), which is connected to the
intermodule bus (IMB), and subsequently the CPU. This configuration allows the CPU to access the
data and control registers in each CTM6 submodule on the SMB. Four local time base buses TBB[1:4],
each 16-bits wide, are used to transfer timing information from counters to action submodules. Each
CTM6 submodule can be connected to two TBBs. Figure 17 shows a block diagram of the CTM6.
Freescale Semiconductor, Inc...
6.1 Overview
The time base bus system connects the four counter submodules to the eleven double-action submodules (DASMs) and eight single-action submodules (SASM) channels.
The bus interface unit submodule (BIUSM) allows all the CTM6 submodules to communicate to the IMB
via the submodule bus (SMB).
The counter prescaler submodule (CPSM) generates six different clock frequencies which can be used
by any counter submodule. This submodule is contained within the BIUSM.
The free-running counter submodule (FCSM) has a 16-bit up counter with an associated clock source
selector, selectable time-base bus drivers, software writable control registers, software readable status
bits, and interrupt logic. One FCSM is contained in the CTM6.
The modulus counter submodule (MCSM) is an enhancement of the FCSM. A modulus register gives
the additional flexibility of recycling the counter at a count other than 64K clock cycles. Three MCSMs
are contained in the CTM6.
The single action submodule (SASM) provides an input capture and an output compare for each of two
bidirectional pins. A total of four SASMs (eight channels) are contained in the CTM6.
The double-action submodule (DASM) provides two 16-bit input captures or two 16-bit output compare
functions that can occur automatically without software intervention. Eleven DASMs are contained in
the CTM6.
The real-time clock submodule (RTCSM) provides a real time clock function independent of other CTM6
submodules. This time counter is driven by a dedicated low frequency oscillator (32.768 kHz) for low
power consumption.
A parallel port I/O submodule (PIOSM) handles up to eight input/output pins. Each pin of the PIOSM
may be programmed as an input or an output under software control. One PIOSM is contained in the
CTM6.
The static RAM submodule (RAMSM) provides 32 bytes (16 words) of contiguous memory locations
and takes the address space of four standard submodules. The RAMSM works as a stand-by memory.
Two RAMSMs are contained in the CTM6.
The standby power switch changes the power source of the RTCSM prescaler, counters, and oscillator,
as well as the two RAMSMs to VRTC when VDD drops below its minimum specified value.
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CIO5
CIO4
PORT I/O SUBMODULE
(PIOSM17A)
CIO3
CIO2
CIO1
CIO0
EXTERNAL CLOCK
LOAD
MODULUS COUNTER
SUBMODULE (MCSM30)
CLOCK PRESCALER
SUBMODULE (CPSM)
MODULUS COUNTER
SUBMODULE (MCSM31)
BUS INTERFACE UNIT
SUBMODULE (BIUSM)
CTS24A
SINGLE ACTION
SUBMODULE (SASM24B)
CTS24B
SINGLE ACTION
SUBMODULE (SASM18A)
CTS18A
SINGLE ACTION
SUBMODULE (SASM18B)
CTS18B
DOUBLE ACTION
SUBMODULE (DASM26)
CTD26
DOUBLE ACTION
SUBMODULE (DASM27)
CTD27
DOUBLE ACTION
SUBMODULE (DASM28)
CTD28
DOUBLE ACTION
SUBMODULE (DASM29)
CTD29
LOAD
CTM31L
Freescale Semiconductor, Inc...
SINGLE ACTION
SUBMODULE (SASM24A)
TIME BASE BUS 1
TIME BASE BUS 2
EXTERNAL CLOCK
LOAD
SINGLE ACTION
SUBMODULE (SASM12A)
MODULUS COUNTER
SUBMODULE (MCSM2)
SINGLE ACTION
SUBMODULE (SASM12B)
FREE-RUNNING
COUNTER
SUBMODULE (FCSM3)
SINGLE ACTION
SUBMODULE (SASM14A)
CTS14A
SINGLE ACTION
SUBMODULE (SASM14B)
CTS14B
DOUBLE ACTION
SUBMODULE (DASM4)
CTD4
DOUBLE ACTION
SUBMODULE (DASM5)
CTD5
DOUBLE ACTION
SUBMODULE (DASM6)
CTD6
DOUBLE ACTION
SUBMODULE (DASM7)
CTD7
DOUBLE ACTION
SUBMODULE (DASM8)
CTD8
DOUBLE ACTION
SUBMODULE (DASM9)
CTD9
DOUBLE ACTION
SUBMODULE (DASM10)
CTD10
TIME BASE BUS 4
TIME BASE BUS 3
SRAM SUBMODULE
(RAMSM32)
SRAM SUBMODULE
(RAMSM36)
VDD
VDDSYN
STANDBY POWER
SWITCH
VRTC
VSSRTCOSC
REAL-TIME CLOCK
SUBMODULE (RTCSM16)
EXRTC
XRTC
VSSRTCOSC
GLOBAL TIME BASE BUS A
GLOBAL TIME BASE BUS B
CTM6 BLOCK
Figure 17 CTM6 Block Diagram
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6.2 Address Map
The CTM6 address map occupies 512 bytes. All CTM6 registers are addressable in supervisor space
only. Table 45 shows the CTM6 register.
Table 45 CTM6 Address Map
Freescale Semiconductor, Inc...
Address
15
0
$YFF4001
BIUSM Module Configuration Register (BIUMCR)
$YFF402
BIUSM Test Register (BIUTEST)
$YFF404
BIUSM Time Base Register (BIUTBR)
$YFF406
Reserved
$YFF408
CPSM Control Register (CPCR)
$YFF40A
CPSM Test Register (CPTR)
$YFF40C –$YFF40E
Reserved
$YFF410
MCSM2 Status/Interrupt/Control Register (MCSM2SICR)
$YFF412
MCSM2 Counter Register (MCSM2CNT)
$YFF414
MCSM2 Modulus Latch (MCSM2ML)
$YFF416
Reserved
$YFF418
FCSM3 Status/Interrupt/Control Register (FCSM3SIC)
$YFF41A
FCSM3 Counter Register (FCSM3CNT)
$YFF41C – $YFF41E
Reserved
$YFF420
DASM4 Status/Interrupt/Control Register (DASM4SIC)
$YFF422
DASM4 Register A (DASM4A)
$YFF424
DASM4 Register B (DASM4B)
$YFF426
Reserved
$YFF428
DASM5 Status/Interrupt/Control Register (DASM5SIC)
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$YFF42A
DASM5 Register A (DASM5A)
$YFF42C
DASM5 Register B (DASM5B)
$YFF42E
Reserved
$YFF430
DASM6 Status/Interrupt/Control Register (DASM6SIC)
$YFF432
DASM6 Register A (DASM6A)
$YFF434
DASM6 Register B (DASM6B)
$YFF436
Reserved
$YFF438
DASM7 Status/Interrupt/Control Register (DASM7SIC)
$YFF43A
DASM7 Register A (DASM7A)
$YFF43C
DASM7 Register B (DASM7B)
$YFF43E
Reserved
$YFF440
DASM8 Status/Interrupt/Control Register (DASM8SIC)
$YFF442
DASM8 Register A (DASM8A)
$YFF444
DASM8 Register B (DASM8B)
$YFF446
Reserved
$YFF448
DASM9 Status/Interrupt/Control Register (DASM9SIC)
$YFF44A
DASM9 Register A (DASM9A)
$YFF44C
DASM9 Register B (DASM9B)
$YFF44E
Reserved
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Table 45 CTM6 Address Map (Continued)
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Address
15
0
$YFF450
DASM10 Status/Interrupt/Control Register (DASM10SIC)
$YFF452
DASM10 Register A (DASM10A)
$YFF454
DASM10 Register B (DASM10B)
$YFF456 – $YFF45E
Reserved
$YFF460
SASM12 Status/Interrupt/Control Register A (SIC12A)
$YFF462
SASM12 Data Register A (S12DATA)
$YFF464
SASM12 Status/Interrupt/Control Register B (SIC12B)
$YFF466
SASM12 Data Register B (S12DATB)
$YFF468 – $YFF46E
Reserved
$YFF470
SASM14 Status/Interrupt/Control Register A (SIC14A)
$YFF472
SASM14 Data Register A (S14DATA)
$YFF474
SASM14 Status/Interrupt/Control Register B (SIC14B)
$YFF476
SASM14 Data Register B (S14DATB)
$YFF478 – $YFF47E
Reserved
$YFF480
RTCSM16 Status/Interrupt/Control Register (RTC16SIC)
$YFF482
RTCSM16 Prescaler Register (R16PRR)
$YFF484
RTCSM16 32-Bit Free-Running Counter High (R16FRCH)
$YFF486
RTCSM16 32-Bit Free-Running Counter Low (R16FRCL)
$YFF488
PIOSM17A I/O Port Register (PIO17A)
$YFF48A – $YFF48E
Reserved
$YFF490
SASM18 Status/Interrupt/Control Register A (SIC18A)
$YFF492
SASM18 Data Register A (S18DATA)
$YFF494
SASM18 Status/Interrupt/Control Register B (SIC18B)
$YFF496
SASM18 Data Register B (S18DATB)
$YFF498 –$YFF4BE
Reserved
$YFF4C0
SASM24 Status/Interrupt/Control Register A (SIC24A)
$YFF4C2
SASM24 Data Register A (S24DATA)
$YFF4C4
SASM24 Status/Interrupt/Control Register B (SIC24B)
$YFF4C6
SASM24 Data Register B (S24DATB)
$YFF4C8 – $YFF4CE
Reserved
$YFF4D0
DASM26 Status/Interrupt/Control Register (DASM26SIC)
$YFF4D2
DASM26 Register A (DASM26A)
$YFF4D4
DASM26 Register B (DASM26B)
$YFF4D6
Reserved
$YFF4D8
DASM27 Status/Interrupt/Control Register (DASM27SIC)
$YFF4DA
DASM27 Register A (DASM27A)
$YFF4DC
DASM27 Register B (DASM27B)
$YFF4DE
Reserved
$YFF4E0
DASM28 Status/Interrupt/Control Register (DASM28SIC)
$YFF4E2
DASM28 Register A (DASM28A)
$YFF4E4
DASM28 Register B (DASM28B)
$YFF4E6
Reserved
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Table 45 CTM6 Address Map (Continued)
Freescale Semiconductor, Inc...
Address
15
0
$YFF4E8
DASM29 Status/Interrupt/Control Register (DASM29SIC)
$YFF4EA
DASM29 Register A (DASM29A)
$YFF4EC
DASM29 Register B (DASM29B)
$YFF4EE
Reserved
$YFF4F0
MCSM30 Status/Interrupt/Control Register (MCSM30SIC)
$YFF4F2
MCSM30 Counter Register (MCSM30CNT)
$YFF4F4
MCSM30 Modulus Latch (MCSM30ML)
$YFF4F6
Reserved
$YFF4F8
MCSM31 Status/Interrupt/Control Register (MCSM31SIC)
$YFF4FA
MCSM31 Counter Register (MCSM31CNT)
$YFF4FC
MCSM31 Modulus Latch (MCSM31ML)
$YFF4FE
Reserved
$YFF500 – $YFF51E
RAMSM32 RAM
$YFF520 – $YFF53E
RAMSM36 RAM
$YFF540 – $YFF5FE
Reserved
NOTES:
1. Y = M111, where M is the logic state of the module mapping (MM) bit in the SIMLCR.
6.3 Time Base Bus System
The time base bus system is composed of four 16-bit buses: TBB1, TBB2, TBB3 and TBB4. They are
arranged so that each CTM6 submodule can be connected to two time base buses. Figure 18 shows
that CTM6 submodules numbered 1 to M-1 can be connected to TBB3 and TBB4. CTM6 submodules
M to N can be connected to TBB1 and TBB2. Control bits within each CTM6 submodule allow the software to connect the submodule to the desired time base bus(es).
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TIME BASE BUS A (TBBA)
TIME BASE BUS B (TBBB)
TIME BASE BUS 3 (TBB3)
SUBMODULE BUS (SMB)
TIME BASE BUS 2 (TBB2)
TIME BASE BUS 1 (TBB1)
Freescale Semiconductor, Inc...
SUBMODULE M+1
TIME BASE BUS 4 (TBB4)
SUBMODULE M-1
SUBMODULE M
SUBMODULE 2
SUBMODULE 1
SUBMODULE N
BUS INTERFACE UNIT SUBMODULE (BIUSM)
INTERMODULE BUS (IMB)
CTM TBB BLOCK
Figure 18 Time Base Bus Configuration
As shown in Figure 18, each CTM submodule can access one of two global time base buses. TBB1
and TBB4 are collectively referred to as global time base bus TBBA. Likewise, TBB2 and TBB3 are collectively referred to as global time base bus TBBB. Table 46 shows which time base buses are available
for each CTM6 submodule.
Table 46 CTM6 Time Base Bus Allocation
Global/Local Time Base
Bus Allocation
Global/Local Time Base
Bus Allocation
Submodule
Global Bus A
Global Bus B
Submodule
Global Bus A
Global Bus B
MCSM2
TBB4
TBB3
SASM18
TBB1
TBB2
FCSM3
TBB4
TBB3
SASM24
TBB1
TBB2
DASM4 – 10
TBB4
TBB3
DASM26 – 29
TBB1
TBB2
SASM12 – 14
TBB4
TBB3
MCSM30 – 31
TBB1
TBB2
Time base buses are used to transfer timing information from counters to action submodules. Each
CTM6 submodule can either be a clock source module (and drive one or two of the time base buses)
or an action submodule (and read and react to the timing information on the time base buses).
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The time base buses are precharge/discharge type buses with wired-OR capability, so that no hardware
damage occurs when several counters are driving the same bus at the same time.
6.4 Bus Interface Unit Submodule (BIUSM)
The BIUSM connects the SMB to the IMB and allows the CTM6 submodules to communicate with the
CPU. The BIUSM also communicates interrupt requests from the CTM6 submodules to the IMB, and
transfers the interrupt level, arbitration bit and vector number to the CPU during the interrupt acknowledge cycle.
6.4.1 BIUSM Registers
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The BIUSM contains a module configuration register, a time base register, and a test register. The
BIUSM register block always occupies the first four register locations in the CTM6 register space and
cannot be relocated within the CTM6 structure. All unused bits and reserved address locations return
zero when read by the software. Writing to unused bits and reserved address locations has no effect.
BIUMCR — BIU Module Configuration Register
15
14
13
STOP
FRZ
0
12
VECT[7:6]
11
0
1
10
9
$YFF400
8
IARB[2:0]
7
6
5
4
3
2
1
0
0
0
TBRS1
0
0
0
0
TBRS0
0
0
0
0
0
0
0
0
RESET:
0
0
1
0
0
0
STOP — Stop Enable
The STOP bit, while asserted, completely stops operation of the CTM6. The BIUSM continues to operate to allow the CPU access to submodule registers. The CTM6 remains stopped until reset or until the
STOP bit is negated by the CPU.
0 = Allows operation of the CTM6
1 = Stops operation of the CTM6
FRZ — FREEZE Assertion Response
0 = Ignore IMB FREEZE signal
1 = CTM6 stops when IMB FREEZE signal is asserted
NOTE
Some submodules may validate this signal with internal enable bits.
Bit 13 — Not Implemented
VECT[7:6] — Interrupt Vector Base Number Field
This bit field selects the interrupt vector base number for the CTM6. Of the eight bits necessary for vector number definition, the six least significant bits are programmed by hardware on a submodule basis,
while the two remaining bits are provided by VECT[7:6]. This places the CTM6 vectors in one of four
possible positions in the interrupt vector table. Refer to Table 47.
Table 47 Interrupt Vector Base Number Bit Field
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VECT7
VECT6
Resulting Vector
Base Number
0
0
$00
0
1
$40
1
0
$80
1
1
$C0
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IARB[2:0] — Interrupt Arbitration Field
This bit field and the IARB3 bit within each submodule provide 15 different interrupt arbitration numbers
that can be used to arbitrate between interrupt requests occurring on the IMB with the same interrupt
priority level.
The IARB field defaults to zero on reset, preventing the module from arbitrating during an IACK cycle.
If no arbitration takes place during the IACK cycle, the SIML generates a spurious interrupt, indicating
to the system that the interrupt arbitration number has not been initialized.
The CTM6 allows two different arbitration numbers to be used by providing each submodule with its own
IARB3 bit (which can be set or cleared in software). Once IARB[2:0] are assigned in the BIUSM, they
apply to all CTM6 interrupt requests. Therefore, CTM6 submodule interrupts can be prioritized with requests from other modules at the same interrupt level. IARB[2:0] are cleared by reset.
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Bits[7:6], [4:1] — Not Implemented
TBRS1, TBRS0 — Time Base Register Bus Select Bits
These bits specify which time base bus is accessed when the time base register (BIUTBR) is read. Refer to Table 48.
Table 48 Time Base Register Bus Select Bits
TBRS1
TBRS0
Time Base Bus
0
0
TBB1
0
1
TBB2
1
0
TBB3
1
1
TBB4
BIUTEST — BIUSM Test Register
$YFF402
BIUTEST is used during factory testing of the CTM6. Accesses to BIUTEST must be made while the
MCU is in test mode.
BIUTBR — BIUSM Time Base Register
15
14
$YFF404
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RESET:
0
0
BIUTBR is a read-only register used to read the value present on one of the time base buses. The time
base bus being accessed is determined by TBRS1 and TBRS0 in BIUMCR. Writing to BIUTBR has no
effect during normal operation.
6.5 Counter Prescaler Submodule (CPSM)
The counter prescaler submodule (CPSM) is a programmable divider system that provides the CTM6
counters with a choice of six clock signals (PCLKx) derived from the sixth frequency MCU system clock
(fsys). Five of these frequencies are derived from a fixed divider chain. The divide ratio is software selectable from a choice of four divide ratios.
The CPSM is contained within the BIUSM. Figure 19 shows a block diagram of the CPSM.
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FIRST CPSM
PRESCALER
fsys
fsys ÷ 2
PCLK1 =
÷2 or ÷3
÷2
PCLK2 =
÷4
fsys ÷ 4
fsys ÷ 6
PCLK3 =
fsys ÷ 8
fsys ÷ 12
PCLK4 =
fsys ÷ 16
fsys ÷ 24
PCLK5 =
fsys ÷ 32
fsys ÷ 48
PCLK6 =
fsys ÷ 64
fsys ÷ 128
fsys ÷ 256
fsys ÷ 512
fsys ÷ 96
fsys ÷ 192
fsys ÷ 384
fsys ÷ 768
DIV23 = ÷ 2
DIV23 = ÷ 3
8-BIT
÷8
PRESCALER
÷16
÷32
÷64
SELECT
÷128
÷256
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fsys ÷ 3
PRUN DIV23 PSEL1 PSEL0
CPCR
CTM CPSM BLOCK
Figure 19 CPSM Block Diagram
6.5.1 CPSM Registers
The CPSM contains a control register and a test register. All unused bits and reserved address locations return zero when read by the software. Writing to unused bits and reserved address locations has
no effect.
CPCR — CPSM Control Register
15
14
13
12
11
$YFF408
10
9
8
7
6
5
4
NOT USED
3
2
PRUN
DIV23
0
0
1
0
PSEL[1:0]
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PRUN — Prescaler Running
The PRUN bit is a read/write control bit that allows the software to switch the prescaler counter on and
off. This bit allows the counters in various CTM6 submodules to be synchronized. It is cleared by reset.
0 = Prescaler is held in reset and is not running
1 = Prescaler is running
DIV23 — Divide By 2/Divide By 3
The DIV23 bit is a read/write control bit that selects the division ratio of the first prescaler counter. It may
be changed by the software at any time and is cleared by reset.
0 = First prescaler stage divides by two
1 = First prescaler stage divides by three
PSEL[1:0] — Prescaler Division Ratio Select Field
This bit field selects the division ratio of the programmable prescaler output signal (PCLK6). Refer to
Table 49.
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Table 49 Prescaler Division Ratio Select Field
Freescale Semiconductor, Inc...
Prescaler Control Register Bits
Prescaler Division Ratio
PRUN
DIV23
PSEL1 PSEL0 PCLK1 PCLK2 PCLK3 PCLK4 PCLK5 PCLK6
0
X
X
X
0
0
0
0
0
0
1
0
0
0
2
4
8
16
32
64
1
0
0
1
2
4
8
16
32
128
1
0
1
0
2
4
8
16
32
256
1
0
1
1
2
4
8
16
32
512
1
1
0
0
3
6
12
24
48
96
1
1
0
1
3
6
12
24
48
192
1
1
1
0
3
6
12
24
48
384
1
1
1
1
3
6
12
24
48
768
CPTR — CPSM Test Register
$YFF40A
CPTR is used during factory testing of the CTM6. Accesses to CPTR must be made while the MCU is
in test mode.
6.6 Clock Sources for Counter Submodules
One of seven clock sources can be chosen for each counter submodule. Five of them are fixed
prescaler taps derived from the system clock: ÷2, ÷4, ÷8, ÷16, and ÷32. A sixth prescaler tap is software
selectable as the system clock divided by 64, 128, 256, or 512. An alternate prescaler option provides
fixed prescaler taps of the system clock divided by 3, 6, 12, 24, and 48. In this case, the software selectable tap is the system clock divided by 96, 192, 384, or 768.
The seventh selectable clock source is an external pin which may trigger on the rising or falling edge of
the input signal. The external input allows a clock frequency to be selected that is not based on the MCU
system clock. Alternately, the external clock input allows a counter submodule to be used for pulse or
event counting.
NOTE
The external clock inputs for MCSM30 and MCSM31 are tied to the I/O pin CTD5
for DASM5. The external clock inputs for MCSM2 and FCSM3 are tied to the I/O
pin CTD27 for DASM27.
6.7 Free-Running Counter Submodule (FCSM)
The free-running counter submodule (FCSM) has a 16-bit up counter with an associated clock source
selector, selectable time-base bus drivers, software writable control registers, software readable status
bits, and interrupt logic. When the 16-bit up counter overflows from $FFFF to $0000, an optional overflow interrupt may be generated.
Software selects which, if any, time-base bus is to be driven by the 16-bit counter. A software control
register selects whether the clock input to the counter is one of the taps from the prescaler or an input
pin. The polarity of the external input pin is also programmable.
One FCSM is contained in the CTM6. Figure 20 shows a block diagram of the FCSM.
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NOTE
In order to count, the FCSM requires the CPSM clock signals to be present. On
coming out of reset, the FCSM does not count internal or external events until the
prescaler in the CPSM starts running (when the software sets the PRUN bit). This
allows all counters in the CTM6 submodules to be synchronized.
TBBA
TIME BASE BUSES
TBBB
BUS
SELECT
6 CLOCKS (PCLKX) FROM PRESCALER
DRVA DRVB
Freescale Semiconductor, Inc...
CONTROL REGISTER BITS
INPUT PIN
CTMC
CLOCK
SELECT
EDGE
DETECT
IN
OVERFLOW INTERRUPT
CONTROL
16-BIT UP COUNTER
CLK2 CLK1 CLK0
COF
CONTROL REGISTER BITS
IL2
IL1
IL0
IARB3
CONTROL REGISTER BITS
SUBMODULE BUS
CTM FCSM BLOCK
Figure 20 FCSM Block Diagram
6.7.1 FCSM Registers
The FCSM contains a status/interrupt/control register and a counter register. All unused bits and reserved address locations return zero when read. Writing to unused bits and reserved address locations
has no effect.
FCSM3SIC — FCSM Status/Interrupt/Control Register
15
14
COF
13
12
IL[2:0]
$YFF418
11
10
9
8
7
6
5
4
3
IARB3
0
DRVA
DRVB
IN
0
0
0
0
0
0
0
0
U
0
0
0
0
2
1
0
CLK[2:0]
RESET:
0
0
0
0
0
0
0
COF — Counter Overflow Flag
This status flag indicates whether or not a counter overflow has occurred. An overflow is defined to be
the transition of the counter from $FFFF to $0000. If the IL field is non-zero, an interrupt request is generated when the COF bit is set.
0 = Counter overflow has not occurred
1 = Counter overflow has occurred
This flag is set only by hardware and cleared only by software or a system reset. To clear the flag, first
read the register with COF set to one, then write a zero to the bit. COF is cleared only if no overflow
occurs between the read and write operations.
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IL[2:0] — Interrupt Level
Setting IL[2:0] to a non-zero value causes the FCSM to request an interrupt of the selected level when
the COF bit sets. If IL[2:0] = %000, no interrupt will be requested when COF sets. These bits can be
read or written at any time and are cleared by reset.
IARB3 — Interrupt Arbitration Bit 3
This bit works in conjunction with IARB[2:0] in the BIUMCR. Each module that generates interrupt requests on the IMB must have a unique value in the arbitration field. This interrupt arbitration identification number is used to arbitrate for the IMB when modules generate simultaneous interrupts of the same
priority. The IARB3 bit is cleared by reset. Refer to 6.4.1 BIUSM Registers for more information on
IARB[2:0].
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DRV[A:B] — Drive Time Base Bus
This bit field contains read/write bits that control the connection of the FCSM to the time base buses A
and B. These bits are cleared by reset. Refer to Table 52.
Table 50 Drive Time Base Bus Field
DRVA
DRVB
Bus Selected
0
0
No time base bus driven
0
1
Time base bus B is driven
1
0
Time base bus A is driven
1
1
Both time base buses A and B are driven
WARNING
Two time base buses should not be driven at the same time.
IN — Input Pin Status Bit
This read-only status bit reflects the logic state of the FCSM input pin. Writing to this bit has no effect,
nor does reset.
NOTE
The clock input of FCSM3 is internally connected to I/O pin CTD27 of DASM27 and
will read the state of that pin.
CLK[2:0] — Counter Clock Select
These read/write control bits select one of six internal clock signals (PCLK[1:6]) or one of two external
conditions on the external clock input pin. Maximum frequency of the external clock signals is fsys/4.
Refer to Table 54.
Table 51 Counter Clock Select Field
CLK2
CLK1
CLK0
Free-Running Counter Clock Source
0
0
0
PCLK1 (fsys ÷ 2 or fsys ÷ 3)
0
0
1
PCLK2 (fsys ÷ 4 or fsys ÷ 6)
0
1
0
PCLK3 (fsys ÷ 8 or fsys ÷ 12)
0
1
1
PCLK4 (fsys ÷ 16 or fsys ÷ 24)
1
0
0
PCLK5 (fsys ÷ 32 or fsys ÷ 48)
1
0
1
PCLK6 (fsys ÷ 64 or fsys ÷ 768)
1
1
0
External clock input, falling edge
1
1
1
External clock input, rising edge
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FCSM3CNT — FCSM Counter Register
15
14
$YFF41A
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RESET:
0
0
The FCSM counter register is a read/write register. A read returns the current value of the counter. A
write loads the counter with the specified value. The counter then begins incrementing from this new
value.
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6.8 Modulus Counter Submodule (MCSM)
The modulus counter submodule (MCSM) is an enhancement of the FCSM. The MCSM contains a 16bit modulus latch, a 16-bit loadable up-counter, counter loading logic, a clock selector, a time base bus
driver, and an interrupt interface. A modulus latch gives the additional flexibility of recycling the counter
at a count other than 64-Kbyte clock cycles. The state of the modulus latch is transferred to the counter
when an overflow occurs or when a user-specified edge transition occurs on an external input pin. In
addition, a write to the modulus counter simultaneously loads both the counter and the modulus latch
with the specified value. The counter then begins incrementing from this new value.
Three MCSMs are contained in the CTM6. Figure 21 shows a block diagram of the MCSM.
NOTE
In order to count, the MCSM requires the CPSM clock signals to be present. On
coming out of reset, the MCSM does not count internal or external events until the
prescaler in the CPSM starts running (when the software sets the PRUN bit). This
allows all counters in the CTM6 submodules to be synchronized.
TBBA
TIME BASE BUSES
TBBB
6 CLOCKS (PCLKX) FROM PRESCALER
BUS
SELECT
CLOCK
INPUT PIN
CTMC
CLOCK
SELECT
EDGE
DETECT
DRVA DRVB
CONTROL REGISTER BITS
IN2
CLK2 CLK1 CLK0
CONTROL REGISTER BIT
MODULUS
LOAD INPUT
PIN CTML
CONTROL REGISTER BITS
16-BIT UP COUNTER
OVERFLOW
INTERRUPT
CONTROL
MODULUS
CONTROL
MODULUS LOAD
INPUT PIN CTML
MODULUS REGISTER
EDGE
DETECT
WRITE
BOTH
IN1
CONTROL REGISTER BIT
EDGEN EDGEP
COF
CONTROL REGISTER BITS
IL2
IL1
IL0
IARB3
CONTROL REGISTER BITS
SUBMODULE BUS
CTM MCSM BLOCK
Figure 21 MCSM Block Diagram
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6.8.1 MCSM Registers
The MCSM contains a status/interrupt/control register, a counter, and a modulus latch. All unused bits
and reserved address locations return zero when read. Writing to unused bits and reserved address
locations has no effect. The CTM6 contains three MCSMs, each with its own set of registers.
MCSM2SIC — MCSM2 Status/Interrupt/Control Register
MCSM30SIC — MCSM30 Status/Interrupt/Control Register
MCSM31SIC — MCSM31 Status/Interrupt/Control Register
15
14
COF
13
12
IL[2:0]
$YFF410
$YFF4F0
$YFF4F8
11
10
9
8
7
6
IARB3
0
DRVA
DRVB
IN2
IN1
0
0
0
0
0
0
5
4
EDGEN EDGEP
3
2
0
1
0
CLK[2:0]
RESET:
Freescale Semiconductor, Inc...
0
0
0
0
0
0
0
0
0
0
COF — Counter Overflow Flag
This status flag indicates whether or not a counter overflow has occurred. An overflow of the MCSM
counter is defined to be the transition of the counter from $FFFF to $xxxx, where $xxxx is the value contained in the modulus latch. If the IL[2:0] field is non-zero, an interrupt request is generated when the
COF bit is set.
0 = Counter overflow has not occurred
1 = Counter overflow has occurred
This flag is set only by hardware and cleared only by software or by a system reset. To clear the flag,
the software must first read the register with COF set to one, then write a zero to the bit. COF is cleared
only if no overflow occurs between the read and write operations.
IL[2:0] — Interrupt Level
Setting IL[2:0] to a non-zero value causes the MCSM to request an interrupt of the selected level when
the COF bit sets. If IL[2:0] = %000, no interrupt will be requested when COF sets. These bits can be
read or written at any time and are cleared by reset.
IARB3 — Interrupt Arbitration Bit 3
This bit works in conjunction with IARB[2:0] in the BIUMCR. Each module that generates interrupt requests on the IMB must have a unique value in the arbitration field. This interrupt arbitration identification number is used to arbitrate for the IMB when modules generate simultaneous interrupts of the same
priority. The IARB3 bit is cleared by reset. Refer to 6.4.1 BIUSM Registers for more information on
IARB[2:0].
DRV[A:B] — Drive Time Base Bus
This bit field contains read/write bits that control the connection of the MCSM to time base buses A and
B. These bits are cleared by reset. Refer to Table 52.
Table 52 Drive Time Base Bus Field
DRVA
DRVB
Bus Selected
0
0
No time base bus is driven
0
1
Time base bus B is driven
1
0
Time base bus A is driven
1
1
Both time base buses A and B are driven
WARNING
Two time base buses should not be driven at the same time.
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IN2 — Clock Input Pin Status
This read-only status bit reflects the logic state of the clock input pin. Writing to this bit has no effect,
nor does reset.
NOTE
The clock input of MCSM2 is internally connected to I/O pin CTD27 for DASM27
and will read the state of that pin. The clock inputs of MCSM30 and MCSM31 are
internally connected to I/O pin CTD5 for DASM5 and will read the state of that pin.
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IN1 — Modulus Load Input Pin Status
This read-only status bit reflects the logic state of the modulus load input pin. Writing to this bit has no
effect, nor does reset.
NOTE
The load input of MCSM2 is internally connected to I/O pin CTD29 for DASM29 and
will read the state of that pin. The load input of MCSM30 is internally connected to
I/O pin CTD4 for DASM4 and will read the state of that pin. The load input of
MCSM31 is available externally on the CTM31L pin.
EDGEN, EDGEP — Modulus Load Edge Sensitivity Bits
These read/write control bits select the sensitivity of the edge detection circuitry on the modulus load
pin CTML. Refer to Table 53.
Table 53 Modulus Load Edge Sensitivity
EDGEN
EDGEP
IN1 Edge Detector Sensitivity
0
0
None
0
1
Positive edge only
1
0
Negative edge only
1
1
Positive and negative edge
CLK[2:0] — Counter Clock Select
These read/write control bits select one of six internal clock signals (PCLK[1:6]) or one of two external
conditions on the external clock input pin (rising edge or falling edge). The maximum frequency of the
external clock signals is fsys/4. Refer to Table 54.
Table 54 Counter Clock Select
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CLK2
CLK1
CLK0
Free-Running Counter Clock Source
0
0
0
PCLK1 (fsys ÷ 2 or fsys ÷ 3)
0
0
1
PCLK2 (fsys ÷ 4 or fsys ÷ 6)
0
1
0
PCLK3 (fsys ÷ 8 or fsys ÷ 12)
0
1
1
PCLK4 (fsys ÷ 16 or fsys ÷ 24)
1
0
0
PCLK5 (fsys ÷ 32 or fsys ÷ 48)
1
0
1
PCLK6 (fsys ÷ 64 or fsys ÷ 768)
1
1
0
External clock input, falling edge
1
1
1
External clock input, rising edge
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NOTE
The clock input of MCSM2 is internally connected to I/O pin CTD27 for DASM27
and will read the state of that pin. The clock inputs of MCSM30 and MCSM31 are
internally connected to I/O pin CTD5 for DASM5 and will read the state of that pin.
MCSM2CNT — MCSM2 Counter Register
MCSM30CNT — MCSM30 Counter Register
MCSM31CNT — MCSM31 Counter Register
15
14
$YFF412
$YFF4F2
$YFF4FA
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RESET:
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0
0
The MCSM counter register is a read/write register. A read returns the current value of the counter. A
write simultaneously loads both the counter and the MCSM modulus latch with the specified value. The
counter then begins incrementing from this new value.
MCSM2ML — MCSM2 Modulus Latch
MCSM30ML — MCSM30 Modulus Latch
MCSM31ML — MCSM31 Modulus Latch
15
14
$YFF414
$YFF4F4
$YFF4FC
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RESET:
0
0
The MCSM modulus latch register is a read/write register. A read returns the current value of the latch.
A write pre-loads the latch with a new value that the modulus counter will begin counting from when the
next load condition occurs.
6.9 Single Action Submodule (SASM)
The single action submodule (SASM) provides two identical channels, each having its own input/output
pin, but sharing the same interrupt logic, priority level, and arbitration number. Each channel can be
configured independently to perform either input capture or output compare. Table 55 shows the different operational modes.
Table 55 SASM Operational Modes
Mode
Function
IC1
Input capture either on a rising or falling edge or as a read-only input port
OC2
Output compare
OCT2
OP2
Output compare and toggle
Output port
NOTES:
1. When a channel is operating in IC mode, the IN bit in the SIC register reflects the logic
state of the corresponding input pin (after being Schmitt triggered and synchronized).
2. When a channel is operating in OC, OCT, or OP mode, the IN bit in the SIC register
reflects the logic state of the output of the output flip-flop.
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NOTE
All of the functions associated with one pin are called a SASM channel.
The SASM can perform a single timing action (input capture or output compare) before software intervention is required. Each channel includes a 16-bit comparator and one 16-bit register for saving an input capture value or for holding an output compare value. The input edge detector associated with each
pin is programmable to cause the capture function to occur on the rising or falling edge. The output flip
flop can be set to either toggle when an output compare occurs or to transfer a software-provided bit
value to the output pin. In either input capture or output compare mode, each channel can be programmed to generate an interrupt. One of the two incoming time-base buses may be selected for each
channel. Each channel can also work as a simple I/O pin.
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A total of four SASMs (eight channels) are contained in the CTM6. Figure 22 shows a block diagram
of the SASM.
SINGLE ACTION CHANNEL A
FLAG
IL2
IL1
IL0
IARB3 IEN
I/O PIN
INTERRUPT CONTROL
FLAG
SINGLE ACTION CHANNEL B
I/O PIN
SUBMODULE BUS
CTM TIME BASE BUSES
CTM SASM BLOCK
Figure 22 SASM Block Diagram
6.9.1 SASM Registers
The SASM contains two status/interrupt/control registers (A and B) and two data registers (A and B).
All unused bits and reserved address locations return zero when read. Writing to unused bits and
reserved address locations has no effect. The CTM6 contains four SASMs, each with its own set of registers.
SIC12A, SIC14A — SASM Status/Interrupt/Control Register A
SIC18A, SIC24A — SASM Status/Interrupt/Control Register A
15
14
FLAG
13
12
IL[2:0]
$YFF460, $YFF470
$YFF490, $YFF4C0
11
10
9
8
7
6
IARB3
IEN
0
BSL
IN
0
0
0
0
0
U
0
5
4
FORCE EDOUT
3
2
1
0
0
MODE[1:0]
0
0
0
0
RESET:
0
0
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0
0
0
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SIC12B, SIC14B — SASM Status/Interrupt/Control Register B
SIC18B, SIC24B — SASM Status/Interrupt/Control Register B
$YFF464, $YFF474
$YFF494, $YFF4C4
15
14
13
12
11
10
9
8
7
6
FLAG
0
0
0
0
IEN
0
BSL
IN
0
0
0
0
0
0
0
0
U
0
5
4
FORCE EDOUT
3
2
1
0
0
0
MODE[1:0]
0
0
0
RESET:
0
0
0
0
Freescale Semiconductor, Inc...
SICA and SICB contain the control and status bits for SASM channels A and B, respectively. SICA also
contains the IL[2:0] interrupt level field and IARB3 interrupt arbitration bit 3 for both SASM channels A
and B.
FLAG — Event Flag
FLAG indicates whether or not an input capture or output compare event has occurred. If the IL[2:0]
field is non-zero, and IEN is set, an interrupt request is generated when FLAG is set.
0 = An input capture or output compare event has not occurred
1 = An input capture or output compare event has occurred
Table 56 shows the event flag status during different modes.
Table 56 Event Flag Status Conditions
Mode
Status Description
IC
If a subsequent input capture event occurs while FLAG is set, the new value is latched and
FLAG remains set.
OC
If a subsequent output compare event occurs while FLAG is set, the compare occurs normally
and FLAG remains set.
OCT
If a subsequent output compare event occurs while FLAG is set, the output signal toggles normally and FLAG remains set.
OP
If a subsequent internal compare event occurs while FLAG is set, the compare occurs normally
and FLAG remains set.
FLAG is set only by hardware and cleared only by software or by a system reset.To clear this bit, first
read the register with FLAG set to one, then write a zero to the bit.
NOTE
The flag clearing mechanism works only if no flag setting event occurs between the
read and write operations. If a FLAG setting event occurs between the read and
write operations, the FLAG bit will not cleared.
IL[2:0] — Interrupt Level
Setting IP[2:0] to a non-zero value causes the SASM to request an interrupt when the FLAG bit sets. If
IL[2:0] = %000, no interrupts will be requested when FLAG sets.
NOTE
This field affects both SASM channels, not just channel A.
IARB3 — Interrupt Arbitration Bit 3
This bit works in conjunction with IARB[2:0] in the BIUMCR. Each module that generates interrupt requests on the IMB must have a unique value in the arbitration field. This interrupt arbitration identification number is used to arbitrate for the IMB when modules generate simultaneous interrupts of the same
priority. The IARB3 bit is cleared by reset. Refer to 6.4.1 BIUSM Registers for more information on
IARB[2:0].
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NOTE
This bit field affects both SASM channels, not just channel A.
IEN — Interrupt Enable
This control bit enables interrupts when FLAG is set and the IL[2:0] field is non-zero.
0 = Interrupts disabled
1 = Interrupts enabled
BSL — Time Base Bus Select
This control bit selects the time base bus connected to the SASM.
0 = Time base bus A selected
1 = Time base bus B selected
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IN — Input Pin Status
In input mode (IC), the IN bit reflects the logic state present on the corresponding input pin after being
Schmitt triggered and synchronized.
In the output modes (OC, OCT and OP), the IN bit value reflects the state of the output flip-flop.
The IN bit is a read-only bit. Reset has no effect on this bit.
NOTE
The input of SASM12A is internally connected to I/O pin CTD29 and will read the
state of that pin. The input of SASM12B is internally connected to I/O pin CTD26
and will read the state of that pin.
FORCE — Force Compare Control
In the IC and OP modes, FORCE is not used and writing to it has no effect.
In the OC and OCT modes, FORCE is used by software to cause the output flip-flop (and the output
pin) to behave as though an output compare had occurred. In OC and OCT mode, setting FORCE causes the value of EDOUT to be transferred to the output of the output flip-flop. Internal synchronization
ensures that the correct level appears on the output pin when a new value is written to EDOUT and
FORCE is set at the same time.
0 = No action
1 = Force output flip-flop to behave as if an output compare has occurred
FORCE is cleared by reset and always reads as zero.
NOTE
FLAG is not affected by the use of the FORCE bit.
EDOUT — Edge Detect and Output Level
In IC mode, EDOUT is used to select the edge that triggers the input capture circuitry.
0 = Input capture on falling edge
1 = Input capture on rising edge
In OC and OCT mode, the EDOUT bit is used to latch the value to be output to the pin on the next output
compare match or when the FORCE is set. Internal synchronization ensures that the correct level appears on the output pin when a new value is written to EDOUT and FORCE is set at the same time.
Reading EDOUT returns the previous value written.
In OP mode, the value of EDOUT is output to the corresponding pin. Reading EDOUT returns the previous value written.
MODE[1:0] — SASM Operating Mode
This bit field selects the mode of operation for the SASM channel. Refer to Table 57.
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Table 57 SASM Operating Mode Select
MODE1
MODE2
SASM Channel Operating Mode
0
0
Input capture (IC)
0
1
Output port (OP)
1
0
Output compare (OC)
1
1
Output compare and toggle (OCT)
S12DATA, S14DATA — SASM Data Register A
S18DATA, S24DATA — SASM Data Register A
15
14
$YFF462, $YFF472
$YFF492, $YFF4C2
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
Freescale Semiconductor, Inc...
RESET:
U
U
S12DATB, S14DATB — SASM Data Register B
S18DATB, S24DATB — SASM Data Register B
15
14
$YFF464, $YFF474
$YFF494, $YFF4C4
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
RESET:
U
U
SDATA and SDATB are the data registers associated with SASM channels A and B, respectively. In IC
mode, SDATA and SDATB contain the last captured value. In the OC, OCT and OP modes, SDATA
and SDATB are loaded with the value of the next output compare.
6.10 Double-Action Submodule (DASM)
The double-action submodule (DASM) provides two 16-bit input capture or two 16-bit output compare
functions that can occur automatically without software intervention. The input edge detector is programmable to cause the capture function to occur on user-specified edges. The output flip flop is set by
one of the output compare signals and reset by the other one. The DASM input capture and the output
compare modes may optionally generate interrupts. Software determines which of the two incoming
time-base buses is used for input captures or output compares.
Six operating modes allow software to use DASM input capture and output compare functions to perform pulse-width measurement, period measurement, single pulse generation, and continuous pulse
width modulation, as well as standard input capture and output compare. The DASM can also work as
a single I/O pin. DASM operation is determined by the mode select bit field MODE[3:0] in the DASM
status/interrupt/control (DASMSIC) register. Table 58 shows the different DASM modes of operation.
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Table 58 DASM Modes of Operation
Mode
Description of Mode
DIS
Disabled — I/O pin is placed in a high impedance state
IPWM
Input pulse width measurement — Capture on leading and the trailing edges of an input pulse
IPM
Input period measurement — Capture on two consecutive rising or falling edges of an input pulse
Freescale Semiconductor, Inc...
IC
Input capture — Capture on user-specified edge
OCB
Output compare, flag set on channel B match — Generate leading and trailing edges of an output
pulse and set flag on second edge
OCAB
Output compare, flag set on channels A and B match — Generate leading and trailing edges of an
output pulse and set flag on both edges
OPWM
Output pulse width modulation — Generate continuous PWM output with 7, 9, 11, 12, 13, 14, 15, or
16 bits of resolution
The DASM is composed of two timing channels (A and B), an output flip-flop, an input edge detector,
some control logic and an interrupt interface. All control and status bits are contained in the DASMSIC
register.
Channel A consists of one 16-bit data register and one 16-bit comparator. To the user, channel B also
appears to consist of one 16-bit data register and one 16-bit comparator, though internally, channel B
has two data registers (B1 and B2). The operating mode determines which register is accessed by the
software. Refer to Table 59.
Table 59 Channel B Data Register Access
Mode
Data Register
IPWM, IPM, IC
Registers A and B2 are used to hold the captured values. In these modes,
the B1 register is used as a temporary latch for channel B.
OCA, OCAB
Registers A and B2 are used to define the output pulse. Register B1 is not
used in these modes.
OPWM
Registers A and B1 are used as primary registers and hidden register B2 is
used as a double buffer for channel B.
Register contents are always transferred automatically at the correct time so that the minimum pulse
(measurement or generation) is just one time base bus count. The A and B data registers are always
read/write registers, accessible via the CTM6 submodule bus.
Eleven DASMs are contained in the CTM6. Figure 23 shows a block diagram of the DASM.
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TBBA
2 TIME BASE BUSES
TBBB
BUS
SELECT
FORCA FORCB
BSL
OUTPUT
FLIP-FLOP
16-BIT COMPARATOR A
16-BIT REGISTER A
IN
OUTPUT
BUFFER
I/O PIN
EDPOL
EDGE
DETECT
16-BIT REGISTER B1
Freescale Semiconductor, Inc...
WOR
REGISTER B
INTERRUPT
CONTROL
16-BIT REGISTER B2
16-BIT COMPARATOR B
FLAG
MODE3 MODE2 MODE1 MODE0
CONTROL REGISTER BITS
IL2
IL1
IL0
IARB3
CONTROL REGISTER BITS
SUBMODULE BUS
CTM DASM BLOCK
Figure 23 DASM Block Diagram
6.10.1 DASM Registers
The DASM contains one status/interrupt/control register and two data registers (A and B). All unused
bits and reserved address locations return zero when read. Writing to unused bits and reserved address
locations has no effect. The CTM6 contains 11 DASMs, each with its own set of registers.
DASM4SIC, DASM5SIC — DASM Status/Interrupt/Control Register
DASM6SIC, DASM7SIC — DASM Status/Interrupt/Control Register
DASM8SIC, DASM9SIC — DASM Status/Interrupt/Control Register
DASM10SIC, DASM26SIC — DASM Status/Interrupt/Control Register
DASM27SIC, DASM28SIC — DASM Status/Interrupt/Control Register
DASM29SIC — DASM Status/Interrupt/Control Register
15
14
FLAG
13
12
IL[2:0]
11
10
9
8
7
IARB3
0
WOR
BSL
IN
0
0
0
0
0
6
5
$YFF420, $YFF428
$YFF430, $YFF438
$YFF440, $YFF448
$YFF450, $YFF4D0
$YFF4D8, $YFF4E0
$YFF4E8
4
3
FORCA FORCB EDPOL
2
1
0
MODE[3:0]
RESET:
0
0
0
MC68CK338
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0
0
0
0
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0
0
0
0
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FLAG — Event Flag
This status bit indicates whether or not an input capture or output compare event has occurred. If the
IL[2:0] field is non-zero, an interrupt request is generated when FLAG is set.
0 = An input capture or output compare event has not occurred
1 = An input capture or output compare event has occurred
Table 56 shows the event flag status during different modes.
Table 60 Event Flag Status Conditions
Mode
DIS
IPWM
IPM
Freescale Semiconductor, Inc...
IC
Status Description
FLAG bit is cleared
FLAG bit is set each time there is a capture on channel A
FLAG bit is set each time there is a capture on channel A, except for the first time
FLAG bit is set each time there is a capture on channel A
OCB
FLAG bit is set each time there is a successful comparison on channel B
OCAB
FLAG bit is set each time there is a successful comparison on either channel A or B
OPWM
FLAG bit is set each time there is a successful comparison on channel A
FLAG is set only by hardware and cleared by software or by a system reset. To clear the bit, first read
the register with FLAG set to one, then write a zero to the bit. Placing the DASM in DIS mode will also
clear the flag.
NOTE
The flag clearing mechanism works only if no flag setting event occurs between the
read and write operations. If a FLAG setting event occurs between the read and
write operations, the FLAG bit will not be cleared.
IL[2:0] — Interrupt Level
Setting IL[2:0] to a non-zero value causes the DASM to request an interrupt when the FLAG bit sets. If
IL[2:0] = %000, no interrupt will be requested when FLAG sets.
IARB3 — Interrupt Arbitration Bit 3
This bit works in conjunction with IARB[2:0] in the BIUMCR. Each module that generates interrupt requests on the IMB must have a unique value in the arbitration field. This interrupt arbitration identification number is used to arbitrate for the IMB when modules generate simultaneous interrupts of the same
priority. The IARB3 bit is cleared by reset. Refer to 6.4.1 BIUSM Registers for more information on
IARB[2:0].
WOR — Wired-OR Mode
In the DIS, IPWM, IPM and IC modes, WOR is not used. Reading this bit returns the value that was
previously written.
In the OCB, OCAB and OPWM modes, WOR selects whether the output buffer is configured for normal
or open drain operation.
0 = Output buffer operates in normal mode
1 = Output buffer operates in open drain mode
BSL — Bus Select
This bit selects the time base bus connected to the DASM.
0 = DASM is connected to time base bus A.
1 = DASM is connected to time base bus B.
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IN — Input Pin Status
In the DIS, IPWM, IPM and IC modes, this read-only status bit reflects the logic level on the input pin.
In the OCB, OCAB and OPWM modes, reading this bit returns the value latched on the output flip-flop,
after EDPOL polarity selection.
Writing to this bit has no effect.
FORCA — Force A
In the OCB, OCAB and OPWM modes, FORCA allows software to force the output flip-flop to behave
as if a successful comparison had occurred on channel A (except that the FLAG bit is not set). Writing
a one to FORCA sets the output flip-flop; writing a zero has no effect.
Freescale Semiconductor, Inc...
In the DIS, IPWM, IPM and IC modes, FORCA is not used and writing to it has no effect.
FORCA is cleared by reset, and always reads as zero.
NOTE
Writing a one to both FORCA and FORCB simultaneously resets the output flipflop.
FORCB — Force B
In the OCB, OCAB and OPWM modes, FORCB allows software to force the output flip-flop to behave
as if a successful comparison had occurred on channel B (except that the FLAG bit is not set). Writing
a one to FORCB sets the output flip-flop, writing a zero has no effect.
In the DIS, IPWM, IPM and IC modes, FORCB is not used and writing to it has no effect.
FORCB is cleared by reset, and always reads as zero.
NOTE
Writing a one to both FORCA and FORCB simultaneously resets the output flipflop.
EDPOL — Edge Polarity
EDPOL selects different options depending on the DASM operating mode. Refer to Table 61.
Table 61 Edge Polarity
MODE
EDPOL
DIS
X
EDPOL is not used in DIS mode
0
Channel A captures on a rising edge
Channel B captures on a falling edge
1
Channel A captures on a falling edge
Channel B captures on a rising edge
0
Channel A captures on a rising edge
1
Channel A captures on a falling edge
0
A compare on channel A sets the output pin to logic one
A compare on channel B clears the output pin to logic zero
1
A compare on channel A clears the output pin to logic zero
A compare on channel B sets the output pin to logic one
IPWM
IPM, IC
OCB, OCAB, OPWM
Function
MODE[3:0] — DASM Mode Select
This bit field selects the operating mode of the DASM. Refer to Table 62.
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NOTE
To avoid spurious interrupts, DASM interrupts should be disabled before changing
the operating mode.
Freescale Semiconductor, Inc...
Table 62 DASM Mode Select Field
MODE[3:0]
Bits of
Resolution
Time Base
Bits Ignored
0000
—
—
DIS — Disabled
0001
16
—
IPWM — Input pulse width measurement
0010
16
—
IPM — Input measurement period
0011
16
—
IC — Input capture
0100
16
—
OCB — Output compare, flag on B compare
0101
16
—
OCAB — Output compare, flag on A and B compare
DASM Operating Mode
011X
—
—
Not used
1000
16
—
OPWM — Output pulse-width modulation
1001
15
15
OPWM — Output pulse-width modulation
1010
14
[15:14]
OPWM — Output pulse-width modulation
1011
13
[15:13]
OPWM — Output pulse-width modulation
1100
12
[15:12]
OPWM — Output pulse-width modulation
1101
11
[15:11]
OPWM — Output pulse-width modulation
1110
9
[15:9]
OPWM — Output pulse-width modulation
1111
7
[15:7]
OPWM — Output pulse-width modulation
DASM4A, DASM5A — DASM Data Register A
DASM6A, DASM7A — DASM Data Register A
DASM8A, DASM9A — DASM Data Register A
DASM10A, DASM26A — DASM Data Register A
DASM27A, DASM28A —DASM Data Register A
DASM29A — DASM Data Register A
15
14
$YFF422, $YFF42A
$YFF432, $YFF43A
$YFF442, $YFF44A
$YFF452, $YFF4D2
$YFF4DA, $YFF4E2
$YFF4EA
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
RESET:
U
U
DASMA is the data register associated with channel A. Table 63 shows how the DASMA is used with
the different operating modes.
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Table 63 DASMA Operations
Mode
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DIS
DASMA Operation
DASMA can be accessed to prepare a value for a subsequent mode selection
IPWM
DASMA contains the captured value corresponding to the trailing edge of the measured pulse
IPM
DASMA contains the captured value corresponding to the most recently detected user-specified
rising or falling edge
IC
DASMA contains the captured value corresponding to the most recently detected user-specified
rising or falling edge
OCB
DASMA is loaded with the value corresponding to the leading edge of the pulse to be generated.
Writing to DASMA in the OCB and OCAB modes also enables the corresponding channel A comparator until the next successful comparison.
OCAB
DASMA is loaded with the value corresponding to the leading edge of the pulse to be generated.
Writing to DASMA in the OCB and OCAB modes also enables the corresponding channel A comparator until the next successful comparison.
OPWM
DASMA is loaded with the value corresponding to the leading edge of the PWM pulse to be generated.
DASM4B, DASM5B — DASM Data Register B
DASM6B, DASM7B — DASM Data Register B
DASM8B, DASM9B — DASM Data Register B
DASM10B, DASM26B — DASM Data Register B
DASM27B, DASM28B — DASM Data Register B
DASM29B — DASM Data Register B
15
14
$YFF424, $YFF42C
$YFF434, $YFF43C
$YFF444, $YFF44C
$YFF454, $YFF4D4
$YFF4DC, $YFF4E4
$YFF4EC
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
RESET:
U
U
DASMB is the data register associated with channel B. Table 64 shows how DASMB is used with the
different operating modes. Depending on the mode selected, software access is to register B1 or register B2.
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Freescale Semiconductor, Inc...
Table 64 DASMB Operations
Mode
DASMB Operation
DIS
DASMB can be accessed to prepare a value for a subsequent mode selection. In this mode, register
B1 is accessed in order to prepare a value for the OPWM mode. Unused register B2 is hidden and
cannot be read, but is written with the same value when register B1 is written.
IPWM
DASMB contains the captured value corresponding to the trailing edge of the measured pulse. In this
mode, register B2 is accessed. Buffer register B1 is hidden and cannot be accessed.
IPM
DASMB contains the captured value corresponding to the most recently detected user-specified rising
or falling edge. In this mode, register B2 is accessed. Buffer register B1 is hidden and cannot be
accessed.
IC
DASMB contains the captured value corresponding to the most recently detected user-specified rising
or falling edge. In this mode, register B2 is accessed. Buffer register B1 is hidden and cannot be
accessed.
OCB
DASMB is loaded with the value corresponding to the trailing edge of the pulse to be generated. Writing
to DASMB in the OCB and OCAB modes also enables the corresponding channel B comparator until
the next successful comparison. In this mode, register B2 is accessed. Buffer register B1 is hidden and
cannot be accessed.
OCAB
DASMB is loaded with the value corresponding to the trailing edge of the pulse to be generated. Writing
to DASMB in the OCB and OCAB modes also enables the corresponding channel B comparator until
the next successful comparison. In this mode, register B2 is accessed. Buffer register B1 is hidden and
cannot be accessed.
OPWM
DASMB is loaded with the value corresponding to the trailing edge of the PWM pulse to be generated.
In this mode, register B1 is accessed. Buffer register B2 is hidden and cannot be accessed
6.11 Real-Time Clock Submodule (RTCSM) with Low-Power Oscillator
The real -ime clock submodule provides a real-time clock independent of other CTM6 submodules. This
time counter is driven by a dedicated low frequency oscillator (32.768 kHz) for low power consumption.
The RTCSM contains a 15-bit prescaler and a 32-bit free-running counter, from which seconds, minutes, hours and days can be determined. The RTCSM can also generate interrupts at one second
intervals. The low-power oscillator, prescaler, and counter portions of the RTCSM may be sustained by
a separate power supply (VRTC) for battery backup when VDD is off. The RTCSM and the low-power
oscillator can be disabled for minimum power consumption on VRTC when VDD is powered off. This is
useful for maximizing the shelf life of the standby battery. Refer to 6.14 RTCSM and RAMSM Standby
Operation for more information.
One RTCSM is contained in the CTM6. Figure 24 shows a block diagram of the RTCSM.
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32.768 kHz
10 pF
1 pF1
1
10 kΩ
EXTAL
XTAL
Freescale Semiconductor, Inc...
1 Hz
32-BIT FREE-RUNNING
COUNTER
15-BIT
PRESCALER
32-BIT FREE-RUNNING
COUNTER BUFFER
15-BIT PRESCALER
BUFFER
INTERRUPT
LOGIC
STATUS, INTERRUPT,
AND CONTROL REGISTER BITS
FLAG
(1 Hz)
ARB3
LOW POWER OSCILLATOR
CONTROL
LOGIC
INTERRUPT LEVEL
WRITE
ENABLE
ENABLE
WEN
EN
SUBMODULE BUS
NOTES:
1. RESISTANCE AND CAPACITANCE BASED ON A TEST CIRCUIT CONSTRUCTED WITH A DAISHINKU DMX-38 32.768 kHz CRYSTAL.
SPECIFIC COMPONENTS MUST BE BASED ON CRYSTAL TYPE. CONTACT CRYSTAL VENDOR FOR EXACT CIRCUIT.
CTM RTC BLOCK
Figure 24 RTCSM Block Diagram
6.11.1 RTCSM Registers
The RTCSM contains one status/interrupt/control register, one 15-bit prescaler register and two 32-bit
free-running counter registers (high and low). All unused bits and reserved address locations return
zero when read. Writing to unused bits and reserved address locations has no effect.
RTC16SIC — RTCSM Status/Interrupt/Control Register
15
14
TICKF
13
12
IL[2:0]
11
10
9
8
IARB3
0
WEN
EN
0
0
0
U
$YFF480
7
6
5
4
3
2
1
0
0
0
0
NOT USED
RESET:
U
0
0
0
0
0
0
0
0
TICKF — 1 Hz Clock Tick Flag
TICKF is set each time the 32-bit free-running counter is incremented. Software can clear TICKF by
reading the bit as a one, then writing a zero to it. If the IL[2:0] field is non-zero, an interrupt request is
generated when TICKF is set.
TICKF is not affected by reset.
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NOTE
TICKF is only cleared if the 32-bit free-running counter does not increment between reading RTC16SIC with TICKF set to one and then writing TICKF to zero.
IL[2:0] — Interrupt Level Field
Setting IL[2:0] to a non-zero value causes the RTCSM to request an interrupt of the selected level when
the TICKF bit sets. If IL[2:0] = %000, no interrupt will be requested when TICKF sets.
Freescale Semiconductor, Inc...
IARB3 — Interrupt Arbitration Bit 3
This bit works in conjunction with IARB[2:0] in the BIUMCR. Each module that generates interrupt requests on the IMB must have a unique value in the arbitration field. This interrupt arbitration identification number is used to arbitrate for the IMB when modules generate simultaneous interrupts of the same
priority. The IARB3 bit is cleared by reset. Refer to 6.4.1 BIUSM Registers for more information on
IARB[2:0].
WEN — Write Enable Control
This bit allows the 15-bit prescaler and the 32-bit free-running counter to be updated. Normally, these
are read-only registers. Regular write operations have no effect. When the WEN bit is written to one, it
sets a latch that allows the 15-bit prescaler and the 32-bit free-running counter to be written. The latch
is automatically reset when the prescaler is written.
To write a new value to the complete counter chain:
• Write a one to the WEN bit.
• Execute a long-word write to the 32-bit free-running counter high (R16FRCH) register.
• Execute a word write to the 15-bit prescaler (R16PRR) register.
WEN cannot be written to one again until the writes to update the prescaler and free-running counter
have been completed. The WEN bit always reads as zero.
EN — RTCSM Enable
This bit selects whether the RTCSM is running or not.
0 = RTCSM is not running
1 = RTCSM is running
The EN bit is not affected by reset. If the RTCSM is not to be used, it is recommended that EN be
cleared as soon as the MCU comes out of reset.
R16PRR — RTCSM Prescaler Register
15
14
$YFF482
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
0
RESET:
U
U
R16PRR contains the synchronized value of the 15-bit prescaler or the value to be loaded into the 15bit prescaler.
NOTE
When the RTCSM is disabled, writing to the 15-bit prescaler and 32-bit freerunning counter may give unpredictable results.
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R16FRCH — RTCSM Free-Running Counter High Register
15
14
$YFF484
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
RESET:
U
U
R16FRCH contains the synchronized high word value of the 32-bit free-running counter or the value to
be loaded into the high word 32-bit free-running counter.
NOTE
When the RTCSM is disabled, writing to the 15-bit prescaler and 32-bit free-running counter may give unpredictable results.
Freescale Semiconductor, Inc...
R16FRCL — RTCSM Free-Running Counter Low Register
15
14
$YFF486
13
12
11
10
9
8
7
6
5
4
3
2
1
0
U
U
U
U
U
U
U
U
U
U
U
U
U
U
RESET:
U
U
R16FRCL contains the synchronized low word value of the 32-bit free-running counter or the value to
be loaded into the low word 32-bit free-running counter.
NOTE
When the RTCSM is disabled, writing to the 15-bit prescaler and 32-bit free-running counter may give unpredictable results.
6.12 Parallel Port I/O Submodule (PIOSM)
The port I/O submodule (PIOSM) provides I/O capability independent of other CTM6 modules. The
PIOSM handles up to eight input/output pins.
One PIOSM is contained in the CTM6. Figure 25 shows a block diagram of the PIOSM.
DATA DIRECTION
REGISTER
OUTPUT DATA
REGISTER
I/O PIN
OUTPUT
DRIVER
OUTPUT DATA BIT
INPUT DATA BIT
INPUT
SUBMODULE BUS
CTM PIOSM BLOCK
Figure 25 PIOSM Block Diagram
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6.12.1 PIOSM Register
The PIOSM control register is composed of two 8-bit registers. The upper eight bits contain the data
register and the lower eight bits contain the data direction register. Each PIOSM pin may be programmed as an input or an output under software control. The data direction register controls whether
the corresponding pins are inputs or outputs.
The PIOSM data register can be read or written by the processor. For pins programmed as outputs, a
read of the data register actually reads the value of the output data latch and not the I/O pin.
PIO17A — PIOSM Control Register
$YFF488
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DATA7
DATA6
DATA5
DATA4
DATA3
DATA2
DATA1
DATA0
DDR7
DDR6
DDR5
DDR4
DDR3
DDR2
DDR1
DDR0
U
U
U
U
U
U
0
0
0
0
0
0
0
0
RESET:
Freescale Semiconductor, Inc...
0
0
CTIO[7:6] are not bonded to pins on the MC68338. When one of these signals is configured as an input,
a read of the corresponding data bit always returns a zero. When one of these signals is configured as
an output, a read of the corresponding data bit returns the value stored in the output data latch.
NOTE
Care should be taken when a single word write cycle is used to modify the data register and data direction register of the PIOSM. Undesired glitches can occur on pins
that change from inputs to outputs and vice versa. To avoid this, first use a byte
write cycle to modify the data register then use another byte write cycle to modify
the data direction register.
6.13 Static RAM Submodule (RAMSM)
The static RAM submodule (RAMSM) provides 32 bytes (16 words) of contiguous memory locations
and is not relocatable. It is especially useful for storage of variables and system parameters that must
be maintained when the rest of the MCU is powered down. Data can be read or written in bytes, words,
or long words. RAMSM locations are not affected by reset.
The CTM6 has two RAMSMs. Table 65 shows the RAMSM address locations.
Table 65 RAMSM Address Locations
Static RAM Submodule
Address
32
$YFF500–51E
36
$YFF520–53E
6.14 RTCSM and RAMSM Standby Operation
The standby power switch in CTM6 monitors VDD and selects either VDD and VDDSYN or VRTC for the
power source of the RTCSM and RAMSMs, depending on the level of VDD.
When VDD is within the specified operating range, the RTCSM low-power oscillator is powered by
VDDSYN and the RAMSMs are powered by VDD. VDD also provides power to the digital logic portion of
the RTCSM, therefore both VDD and VDDSYN must be kept equal to each other for normal operation.
When VDD and VDDSYN are powered down, the submodules are powered by VRTC and are in standby
mode. In standby mode, the RTCSM continues to keep time if enabled. However, updates to the 15-bit
prescaler and 32-bit free-running counter buffer registers are halted in order to conserve power. All
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RTCSM registers are write protected in standby mode to prevent loss of data in runaway situations. For
the same reason, the RAMSMs are also write protected in standby mode.
If the standby mode function is not required in a given application, VRTC should be powered from the
VDD and VDDSYN supply. Unpredictable operation of the RAMSMs and RTCSM may result otherwise.
6.15 CTM6 Interrupts
The CTM6 is able to request numerous interrupts on the IMB. Each submodule that is able to request
interrupts can do so with any of seven levels. Each submodule that is able to request interrupts includes
a 3-bit level number and a 1-bit arbitration number that is initialized by software.
Freescale Semiconductor, Inc...
The 3-bit level number selects which of seven interrupt signals on the IMB are driven by that submodule
to create an interrupt request. Of the four priority bits provided on the IMB during arbitration among the
modules, one of them comes from the chosen submodule, and the BIUSM provides the other three.
Thus, the CTM6 responds to two of the possible 15 arbitration numbers.
During the IMB arbitration process, the BIUSM manages the separate arbitration among the CTM6 submodules to determine which submodule should respond. Of the submodules which have an interrupt
request pending at the level being arbitrated on the IMB, the submodule which has the lowest address
is given the highest priority to respond.
When the IARB number is not unique for a given module, simultaneous interrupts are prioritized in hardware according to the vector number or the submodule interrupt arbitration sequence number shown in
Table 66. Following the interrupt arbitration process, the CTM6 provides an 8-bit vector number. Six of
the eight bits are provided by the submodules. A submodule can identify two separate interrupt sources
with unique interrupt vectors. The two high-order bits of the 8-bit vector are provided by the BIUSM. The
six low-order vector bits identify the highest priority interrupt request pending in the CTM6 at the beginning of the arbitration cycle.
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Freescale Semiconductor, Inc...
Table 66 CTM6 Interrupt Priority and Vector/Pin Allocation
Submodule
Name
Submodule Base
Address1
Submodule Interrupt
Vector Number2
Submodule Interrupt Arbitration
Sequence Number3
BIUSM
$YFF400
None
None
CPSM
$YFF408
None
None
MCSM2
$YFF410
xx000010
2
FCSM3
$YFF418
xx000011
3
DASM4
$YFF420
xx000100
4
DASM5
$YFF428
xx000101
5
DASM6
$YFF430
xx000110
6
DASM7
$YFF438
xx000111
7
DASM8
$YFF440
xx001000
8
DASM9
$YFF448
xx001001
9
DASM10
$YFF450
xx001010
10
SASM12
$YFF460
xx001100
12
SASM14
$YFF470
xx001110
14
RTCSM16
$YFF480
xx010000
16
PIOSM17A
$YFF488
—
—
SASM18
$YFF490
xx010010
18
SASM24
$YFF4C0
xx011000
24
DASM26
$YFF4D0
xx011010
26
DASM27
$YFF4D8
xx011011
27
DASM28
$YFF4E0
xx011100
28
DASM29
$YFF4E8
xx011101
29
MCSM30
$YFF4F0
xx011110
30
MCSM31
$YFF4F8
xx011111
31
RAMSM32
$YFF500
—
—
RAMSM36
$YFF520
—
—
NOTES:
1. Y = m111, where m is the state of the MM bit in SIMLCR of the SIML (Y = $7 or $F).
2. “xx” represents VECT[7:6], which is located in the BIUSM module configuration register.
3. Submodule interrupt arbitration number 2 is the highest priority; arbitration number 63 is the lowest
priority.
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7 Electrical Characteristics
This section contains electrical specification tables and reference timing diagrams.
Table 67 Maximum Ratings
Freescale Semiconductor, Inc...
Num
Symbol
Value
Unit
1
Supply
Voltage1, 2, 3
Rating
VDD
– 0.3 to + 6.5
V
2
Input Voltage1, 2, 3, 4
Vin
– 0.3 to + 6.5
V
3
Instantaneous Maximum Current
Single pin limit (applies to all pins)1, 3, 5, 6
ID
25
mA
4
Operating Maximum Current
Digital Input Disruptive Current5, 6, 7
VSS – 0.3 ≤ VIN ≤ VDD + 0.3
IID
– 500 to + 500
µA
5
Operating Temperature Range
TA
TL to TH
°C
– 40 to + 85
6
Storage Temperature Range
Tstg
– 55 to + 150
°C
NOTES:
1. Permanent damage can occur if maximum ratings are exceeded. Exposure to voltages or currents in excess
of recommended values affects device reliability. Device modules may not operate normally while being exposed to electrical extremes.
2. Although sections of the device contain circuitry to protect against damage from high static voltages or electrical fields, take normal precautions to avoid exposure to voltages higher than maximum-rated voltages.
3. This parameter is periodically sampled rather than 100% tested.
4. All pins except TSC.
5. All functional non-supply pins are internally clamped to VSS for transitions below VSS. All functional pins except
EXTAL and XFC are internally clamped to VDD for transitions below VDD.
6. Power supply must maintain regulation within operating VDD range during instantaneous and operating maximum current conditions.
7. Total input current for all digital input-only and all digital input/output pins must not exceed 10 mA. Exceeding
this limit can cause disruption of normal operation.
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Table 68 Thermal Characteristics
Num
1
Characteristic
Symbol
Value
Unit
ΘJA
48
°C/W
Thermal Resistance
Plastic 144-Pin Surface Mount
The average chip-junction temperature (TJ) in C can be obtained from:
T J = T A + ( P D × Θ JA ) (1)
Freescale Semiconductor, Inc...
where:
TA
= Ambient Temperature, °C
ΘJA
= Package Thermal Resistance, Junction-to-Ambient, °C/W
PD
= PINT + PI/O
PINT
= IDD × VDD, Watts — Chip Internal Power
PI/O
= Power Dissipation on Input and Output Pins — User Determined
For most applications PI/O < PINT and can be neglected. An approximate relationship between
PD and TJ (if PI/O is neglected) is:
P D = K ÷ ( T J + 273°C ) (2)
Solving equations 1 and 2 for K gives:
K = P D + ( T A + 273°C ) + Θ JA × P D2 (3)
where K is a constant pertaining to the particular part. K can be determined from equation (3)
by measuring PD (at equilibrium) for a known TA. Using this value of K, the values of PD and TJ
can be obtained by solving equations (1) and (2) iteratively for any value of TA.
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Table 69 Clock Control Timing
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)
Freescale Semiconductor, Inc...
Num
Characteristic
Range1
Symbol
Min
Max
Unit
1
PLL Reference Frequency
fref
25
50
kHz
2
System Frequency2
On-Chip PLL System Frequency Range
External Clock Operation
fsys
dc
4(fref)
dc
14.4
14.4
14.4
MHz
3
PLL Lock Time1, 3, 4, 5, 6
tlpll
—
20
ms
fVCO
—
2 (fsys max)
MHz
Frequency7
4
VCO
5
Limp Mode Clock Frequency
SYNCR X bit = 0
SYNCR X bit = 1
flimp
—
—
fsys max/2
fsys max
MHz
6
CLKOUT Jitter1, 4, 5, 6, 8
Short term (5 µs interval)
Long term (500 µs interval)
Jclk
– 0.5
– 0.05
0.5
0.05
%
NOTES:
1. Tested with a 32.768 kHz reference.
2. All internal registers retain data at 0 Hz.
3. Assumes that stable VDDSYN is applied, and that the crystal oscillator is stable. Lock time is measured from
the time VDD and VDDSYN are valid until RESET is released. This specification also applies to the period required for PLL lock after changing the W and Y frequency control bits in the synthesizer control register (SYNCR) while the PLL is running, and to the period required for the clock to lock after LPSTOP.
4. This parameter is periodically sampled rather than 100% tested.
5. Assumes that a low-leakage external filter network is used to condition clock synthesizer input voltage. Total
external resistance from the XFC pin due to external leakage must be greater than 15 MΩ to guarantee this
specification. Filter network geometry can vary depending upon operating environment.
6. Proper layout procedures must be followed to achieve specifications.
7. Internal VCO frequency (fVCO) is determined by SYNCR W and Y bit values.
The SYNCR X bit controls a divide-by-two circuit that is not in the synthesizer feedback loop.
When X = 0, the divider is enabled, and fsys = fVCO ÷ 4.
When X = 1, the divider is disabled, and fsys = fVCO ÷ 2.
X must equal one when operating at maximum specified fsys.
8. Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum fsys. Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise injected into the PLL circuitry via VDDSYN and VSS and variation in crystal oscillator
frequency increase the Jclk percentage for a given interval. When clock jitter is a critical constraint on control
system operation, this parameter should be measured during functional testing of the final system.
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Table 70 DC Characteristics
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)
Freescale Semiconductor, Inc...
Num
Characteristic
Symbol
Min
Max
Unit
1
Input High Voltage
VIH
0.7 (VDD) VDD + 0.3
V
2
Input Low Voltage
VIL
VSS – 0.3 0.2 (VDD)
V
3
Input
4
Hysteresis1
VHYS
0.5
—
V
Input Leakage Current2
Vin = VDD or VSS Input-only pins
IIN
–2.5
2.5
µA
5
High Impedance (Off-State) Leakage Current2
Vin = VDD or VSS All input/output and output pins
IOZ
–2.5
2.5
µA
6
CMOS Output High Voltage2, 3
IOH = –10.0 µA
Group 1, 2, 4 input/output and all output pins
VOH
VDD – 0.2
—
V
7
CMOS Output Low Voltage2
IOL = 10.0 µA
Group 1, 2, 4 input/output and all output pins
VOL
—
0.2
V
8
Output High Voltage2, 3
IOH = –0.4 mA
Group 1, 2, 4 input/output and all output pins
VOH
VDD – 0.5
—
V
9
Output Low Voltage2
IOL = 0.8 mA Group 1 I/O Pins, CLKOUT, FREEZE/QUOT,
IPIPE/DSO
IOL = 2.65 mA Group 2 and Group 4 I/O Pins, CSBOOT, BG/CS1
IOL = 6 mA
Group 3
VOL
—
—
—
0.4
0.4
0.4
V
10
Three State Control Input High Voltage
VIHTSC
2.7 (VDD)
9.1
V
IMSP
—
–8
–95
—
µA
Current4
11
Data Bus Mode Select Pull-up
Vin = VIL
DATA[15:0]
DATA[15:0]
Vin = VIH
12
VDD Supply Current5
Run6
LPSTOP, (STCPU = 0, External clock input frequency = max fsys)
LPSTOP, (STCPU = 1, External clock input frequency = max fsys)
STOP7, (STCPU = 1, External clock input frequency = max fsys)
IDD
SIDD
SIDD
SIDD
—
—
—
46
2
18
13
mA
mA
mA
mA
13
VRTC Voltage
VSB
2.2
3.6
V
—
—
—
1.0
0.200
0
µA
µA
µA
IDDSYN
—
—
—
750
1.5
300
µA
mA
µA
PD
—
171
mW
Current8
14
15
16
VRTC
CTM6-RTCSM oscillator enabled, VDD = VSS
CTM6-RTCSM oscillator disabled, VDD = VSS
VDD = VDDSYN ≥ 2.7 V
VDDSYN Supply Current5
VCO on, 32.768 kHz crystal reference, maximum fsys
External Clock, maximum fsys
LPSTOP, 32.768 kHz crystal reference, VCO off (STSIM = 0)
Power Dissipation9
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Table 70 DC Characteristics (Continued)
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)
Freescale Semiconductor, Inc...
Num
Characteristic
Symbol
Min
Max
Unit
—
—
10
20
pF
—
—
—
—
90
100
130
200
17
Input Capacitance2, 10
All input-only pins
All input/output pins
CIN
18
Load Capacitance2
Group 1 I/O Pins, CLKOUT, FREEZE/QUOT, IPIPE/DSO
Group 2 I/O Pins and CSBOOT, BG/CS1
Group 3 I/O Pins
Group 4 I/O Pins
CL
pF
NOTES:
1. Applies to:
CTM6 pins
QSM pins
IRQ[7:1], RESET, EXTAL, TSC, RMC, BKPT/DSCLK, IFETCH/DSI
2. Input-Only Pins: TSC, BKPT/DSCLK, RXD
Output-Only Pins: CSBOOT, BG/CS1, CLKOUT, FREEZE/QUOT, IPIPE/DSO
Input/Output Pins:
Group 1: DATA[15:0], IFETCH/DSI, all CTM6 pins except CTM31L
Group 2: ADDR[23:19]/CS[10:6], FC[2:0]/CS[5:3], DSACK[1:0], AVEC, RMC, DS, AS, SIZ[1:0],IRQ[7:1,
MODCLK, ADDR[18:0], R/W, BERR, BR/CS0, BGACK/CS2, PCS[3:1], PCS0/SS, TXD
Group 3: HALT, RESET
Group 4: MISO, MOSI, SCK
3. Does not apply to HALT and RESET because they are open drain pins.
Does not apply to MISO, MOSI, SCK, PCS0/SS, PCS[3:1], and TXD in wired-OR mode.
Does not apply to CTD[29:26] and CTD[10:4] in wired-OR mode.
4. Use of an active pulldown device is recommended.
5. Total operating current is the sum of the appropriate VDD supply and VDDSYN supply current.
6. Current measured with system clock frequency of 14.4 MHz, all modules active.
7. LPSTOP with STCPU = 1 (clock turned off at CPU32L but IMB clock active) plus QSM and CTM6 STOP bits
set.
8. VRTC current measured when VDD and VDDSYN are equal to VSS and VRTC is equal to VSBMAX.
9. Power dissipation is measured with a system clock frequency of 14.4 MHz, all modules active. Power dissipation is calculated using the following expression:
PD = 3.6V (IDDSYN + IDD)
10. Input capacitance is periodically sampled rather than 100% tested.
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Table 71 AC Timing
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)1
Num
Freescale Semiconductor, Inc...
F1
Characteristic
Frequency of Operation
Symbol
Min
Max
Unit
f
0
14.4
MHz
1
Clock Period
tcyc
69.4
—
ns
1A
ECLK Period
tEcyc
555
—
ns
1B
External Clock Input Period2
tXcyc
69.4
—
ns
2, 3
Clock Pulse Width
tCW
24.7
—
ns
2A, 3A ECLK Pulse Width
tECW
277.5
—
ns
2B, 3B External Clock Input High/Low Time2
tXCHL
34.7
—
ns
tCrf
—
10
ns
trf
—
10
ns
4, 5
CLKOUT Rise and Fall Time
4A, 5A Rise and Fall Time — All Outputs Except CLKOUT
6
Clock High to ADDR, FC, SIZE, RMC Valid
tCHAV
0
35
ns
7
Clock High to ADDR, DATA, FC, SIZE, RMC High Impedance
tCHAZx
0
69
ns
8
Clock High to ADDR, FC, SIZE, RMC Invalid
tCHAZn
0
—
ns
9
Clock Low to AS, DS, CS Asserted
tCLSA
2
25
ns
9A
AS to DS or CS Asserted (Read)3
tSTSA
–15
15
ns
9C
Clock Low to IFETCH, IPIPE Asserted
tCLIA
2
31
ns
11
ADDR, FC, SIZE, RMC Valid to AS, CS, (and DS Read) Asserted
tAVSA
15
—
ns
12
Clock Low to AS, DS, CS Negated
tCLSN
2
35
ns
Clock Low to IFETCH, IPIPE Negated
tCLIN
2
31
ns
13
AS, DS, CS Negated to ADDR, FC SIZE Invalid (Address Hold)
tSNAI
19
—
ns
14
AS, CS (and DS Read) Width Asserted
tSWA
138
—
ns
12A
14A
DS, CS Width Asserted (Write)
tSWAW
44
—
ns
14B
AS, CS (and DS Read) Width Asserted (Fast Cycle)
tSWDW
44
—
ns
tSN
44
—
ns
15
AS, DS, CS Width Negated4
16
Clock High to AS, DS, R/W High Impedance
tCHSZ
—
69
ns
17
AS, DS, CS Negated to R/W High
tSNRN
19
—
ns
18
Clock High to R/W High
tCHRH
0
35
ns
20
Clock High to R/W Low
tCHRL
0
35
ns
21
R/W High to AS, CS Asserted
tRAAA
19
—
ns
22
R/W Low to DS, CS Asserted (Write)
tRASA
80
—
ns
23
Clock High to Data Out Valid
tCHDO
—
35
ns
24
Data Out Valid to Negating Edge of AS, CS (Fast Write Cycle)
tDVASN
19
—
ns
25
DS, CS Negated to Data Out Invalid (Data Out Hold)
tSNDOI
19
—
ns
26
Data Out Valid to DS, CS Asserted (Write)
tDVSA
19
—
ns
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Table 71 AC Timing (Continued)
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)1
Num
Symbol
Min
Max
Unit
tDICL
5
—
ns
Late BERR, HALT Asserted to Clock Low (Setup Time)
tBELCL
25
—
ns
AS, DS Negated to DSACK[1:0], BERR, HALT, AVEC Negated
tSNDN
0
100
ns
tSNDI
0
—
ns
DS, CS Negated to Data In High Impedance5, 6
tSHDI
—
65
ns
CLKOUT Low to Data In Invalid (Fast Cycle Hold)5
tCLDI
19
—
ns
CLKOUT Low to Data In High Impedance5
tCLDH
—
100
ns
31
DSACK[1:0] Asserted to Data In Valid7
tDADI
—
58
ns
33
Clock Low to BG Asserted/Negated
tCLBAN
—
35
ns
tBRAGA
1
—
tcyc
tGAGN
1
2
tcyc
27
27A
28
29
29A
30
Freescale Semiconductor, Inc...
30A
Characteristic
Data In Valid to Clock Low (Data Setup)
DS, CS Negated to Data In Invalid (Data In
Hold)5
Asserted)8
35
BR Asserted to BG Asserted (RMC Not
37
BGACK Asserted to BG Negated
39
BG Width Negated
tGH
2
—
tcyc
39A
BG Width Asserted
tGA
1
—
tcyc
R/W Width Asserted (Write or Read)
tRWA
174
—
ns
46A
R/W Width Asserted (Fast Write or Read Cycle)
tRWAS
104
—
ns
47A
Asynchronous Input Setup Time
BR, BGACK, DSACK[1:0], BERR, AVEC, HALT
tAIST
10
—
ns
47B
Asynchronous Input Hold Time
tAIHT
19
—
ns
48
DSACK[1:0] Asserted to BERR, HALT Asserted9
tDABA
—
35
ns
53
Data Out Hold from Clock High
tDOCH
0
—
ns
54
Clock High to Data Out High Impedance
tCHDH
—
35
ns
55
R/W Asserted to Data Bus Impedance Change
tRADC
55
—
ns
56
RESET Pulse Width (Reset Instruction)
tHRPW
512
—
tcyc
57
BERR Negated to HALT Negated (Rerun)
tBNHN
0
—
ns
70
Clock Low to Data Bus Driven (Show Cycle)
tSCLDD
0
35
ns
71
Data Setup Time to Clock Low (Show Cycle)
tSCLDS
19
—
ns
72
Data Hold from Clock Low (Show Cycle)
tSCLDH
10
—
ns
73
BKPT Input Setup Time
tBKST
19
—
ns
74
BKPT Input Hold Time
tBKHT
13
—
ns
75
Mode Select Setup Time (DATA[15:0], MODCLK, BKPT)
tMSS
20
—
tcyc
76
Mode Select Hold Time (DATA[15:0], MODCLK, BKPT)
tMSH
0
—
ns
tRSTA
4
—
tcyc
tRSTR
—
10
tcyc
46
Time10
77
RESET Assertion
78
RESET Rise Time11, 12
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NOTES:
1. All AC timing is shown with respect to 20% VDD and 70% VDD levels unless otherwise noted.
2. When an external clock is used, minimum high and low times are based on a 50% duty cycle. The minimum
allowable tXcyc period is reduced when the duty cycle of the external clock varies. The relationship between external clock input duty cycle and minimum tXcyc is expressed:
Minimum tXcyc period = minimum tXCHL / (50% – external clock input duty cycle tolerance).
3. Specification 9A is the worst-case skew between AS and DS or CS. The amount of skew depends on the relative
loading of these signals. When loads are kept within specified limits, skew will not cause AS and DS to fall outside the limits shown in specification 9.
4. If multiple chip selects are used, CS width negated (specification 15) applies to the time from the negation of a
heavily loaded chip select to the assertion of a lightly loaded chip select. The CS width negated specification
between multiple chip selects does not apply to chip selects being used for synchronous ECLK cycles.
5. Hold times are specified with respect to DS or CS on asynchronous reads and with respect to CLKOUT on fast
cycle reads. The user is free to use either hold time.
6. Maximum value is equal to (tcyc / 2) + 25 ns.
7. If the asynchronous setup time (specification 47A) requirements are satisfied, the DSACK[1:0] low to data setup
time (specification 31) and DSACK[1:0] low to BERR low setup time (specification 48) can be ignored. The data
must only satisfy the data-in to clock low setup time (specification 27) for the following clock cycle. BERR must
satisfy only the late BERR low to clock low setup time (specification 27A) for the following clock cycle.
8. To ensure coherency during every operand transfer, BG is not asserted in response to BR until after all cycles
of the current operand transfer are complete.
9. In the absence of DSACK[1:0], BERR is an asynchronous input using the asynchronous setup time (specification
47A).
10. After external RESET negation is detected, a short transition period (approximately 2 tcyc) elapses, then the SIML
drives RESET low for 512 tcyc.
11. External assertion of the RESET input can overlap internally-generated resets. To ensure that an external reset
is recognized in all cases, RESET must be asserted for at least 590 CLKOUT cycles.
12. External logic must pull RESET high during this period in order for normal MCU operation to begin.
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1
2
4
3
CLKOUT
5
NOTE: TIMING SHOWN WITH RESPECT TO 20% AND 70% VDD.
68300 CLKOUT TIM
Freescale Semiconductor, Inc...
Figure 26 CLKOUT Output Timing Diagram
1B
2B
4B
3B
EXTAL
5B
NOTE: TIMING SHOWN WITH RESPECT TO 20% AND 70% VDD.
PULSE WIDTH SHOWN WITH RESPECT TO 50% VDD.
68300 EXT CLK INPUT TIM
Figure 27 External Clock Input Timing Diagram
1A
2A
4A
3A
ECLK
5A
NOTE: TIMING SHOWN WITH RESPECT TO 20% AND 70% VDD.
68300 ECLK OUTPUT TIM
Figure 28 ECLK Output Timing Diagram
MC68CK338
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S0
S1
S2
S3
S4
S5
CLKOUT
8
6
ADDR[23:20]
FC[2:0]
SIZ[1:0]
11
15
14
AS
13
Freescale Semiconductor, Inc...
9
DS
9A
12
CS
17
18
20
21
R/W
46
DSACK0
47A
28
DSACK1
29
31
DATA[15:0]
27
29A
BERR
48
27A
HALT
9C
12A
12A
IFETCH
73
74
BKPT
47A
47B
ASYNCHRONOUS
INPUTS
68300 RD CYC TIM
Figure 29 Read Cycle Timing Diagram
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MC68CK338
MC68CK338TS/D
Freescale Semiconductor, Inc.
S0
S1
S2
S3
S4
S5
CLKOUT
6
8
ADDR[23:20]
FC[2:0]
SIZ[1:0]
11
15
14
AS
13
Freescale Semiconductor, Inc...
9
DS
21
9
12
CS
20
22
14A
17
R/W
46
DSACK0
47A
28
DSACK1
55
25
DATA[15:0]
23
26
54
53
BERR
48
27A
HALT
74
73
BKPT
68300 WR CYC TIM
Figure 30 Write Cycle Timing Diagram
MC68CK338
MC68CK338TS/D
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S0
S1
S4
S5
S0
CLKOUT
8
6
ADDR[23:0]
FC[2:0]
SIZ[1:0]
14B
AS
12
9
Freescale Semiconductor, Inc...
DS
CS
20
18
46A
R/W
30
27
30A
DATA[15:0]
29A
73
29
BKPT
74
68300 FAST RD CYC TIM
Figure 31 Fast Termination Read Cycle Timing Diagram
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MC68CK338TS/D
Freescale Semiconductor, Inc.
S0
S1
S4
S5
S0
CLKOUT
6
8
ADDR[23:0]
FC[2:0]
SIZ[1:0]
14B
AS
Freescale Semiconductor, Inc...
9
12
DS
CS
46A
20
R/W
23
24
18
DATA[15:0]
73
25
BKPT
74
68300 FAST WR CYC TIM
Figure 32 Fast Termination Write Cycle Timing Diagram
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S0
S1
S2
S3
S4
S5
S98
A5
A5
A2
CLKOUT
ADDR[23:0]
7
DATA[15:0]
AS
Freescale Semiconductor, Inc...
16
DS
R/W
DSACK0
DSACK1
47A
BR
39A
35
BG
33
33
BGACK
37
68300 BUS ARB TIM
Figure 33 Bus Arbitration Timing Diagram — Active Bus Case
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MC68CK338
MC68CK338TS/D
Freescale Semiconductor, Inc.
A0
A5
A5
A2
A3
A0
CLKOUT
ADDR[23:0]
DATA[15:0]
AS
47A
47A
Freescale Semiconductor, Inc...
BR
35
37
BG
33
33
47A
BGACK
68300 BUS ARB TIM IDLE
Figure 34 Bus Arbitration Timing Diagram — Idle Bus Case
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S0
S41
S42
S43
S0
S1
S2
CLKOUT
6
8
ADDR[23:0]
18
R/W
20
AS
9
12
15
DS
Freescale Semiconductor, Inc...
71
70
72
DATA[15:0]
73
74
BKPT
SHOW CYCLE
START OF EXTERNAL CYCLE
NOTE:
Show cycles can stretch during clock phase S42 when bus accesses take longer than two cycles due to IMB module
wait-state insertion.
68300 SHW CYC TIM
Figure 35 Show Cycle Timing Diagram
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MC68CK338TS/D
Freescale Semiconductor, Inc.
S0
S1
S2
S3
S4
S5
S0
S1
S2
S3
S4
S5
CLKOUT
6
8
6
ADDR[23:0]
FC[2:0]
SIZ[1:0]
14
11
11
14
13
AS
15
Freescale Semiconductor, Inc...
9
9
DS
9
17
17
21
12
21
12
CS
20
18
18
14A
46
R/W
46
29
25
55
DATA[15:0]
27
29A
53
23
54
68300 CHIP SEL TIM
Figure 36 Chip Select Timing Diagram
77
78
RESET
75
DATA[15:0],
MODCLK,
BKPT
76
68300 RST/MODE SEL TIM
Figure 37 Reset and Mode Select Timing Diagram
MC68CK338
MC68CK338TS/D
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Table 72 Background Debugging Mode Timing
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)1
Freescale Semiconductor, Inc...
Num
Characteristic
Symbol
Min
Max
Unit
B0
DSI Input Setup Time
tDSISU
19
—
ns
B1
DSI Input Hold Time
tDSIH
13
—
ns
B2
DSCLK Setup Time
tDSCSU
19
—
ns
B3
DSCLK Hold Time
tDSCH
13
—
ns
B4
DSO Delay Time
tDSOD
—
35
ns
B5
DSCLK Cycle Time
tDSCCYC
2
—
tcyc
B6
CLKOUT High to FREEZE Asserted/Negated
tFRZAN
—
64
ns
B7
CLKOUT High to IFETCH High Impedance
tIFZ
—
64
ns
B8
CLKOUT High to IFETCH Valid
tIF
—
64
ns
B9
DSCLK Low Time
tDSCLO
1
—
tcyc
NOTES:
1. All AC timing is shown with respect to 20% VDD and 70% VDD levels unless otherwise noted.
CLKOUT
FREEZE
B3
B2
BKPT/DSCLK
B9
B5
B1
B0
IFETCH/DSI
B4
IPIPE/DSO
68300 BKGD DBM SER COM TIM
Figure 38 Background Debugging Mode Timing Diagram —
Serial Communication
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MC68CK338TS/D
Freescale Semiconductor, Inc.
CLKOUT
B6
FREEZE
B6
B7
IFETCH/DSI
B8
68300 BDM FRZ TIM
Freescale Semiconductor, Inc...
Figure 39 Background Debugging Mode Timing Diagram —
Freeze Assertion
Table 73 ECLK Bus Timing
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH)1
Num
1A
Characteristic
ECLK Period
2A, 3A ECLK Pulse Width
Symbol
Min
Max
Unit
tEcyc
555
—
ns
tECW
277.5
—
ns
E1
ECLK Low to Address Valid2
tEAD
—
70
ns
E2
ECLK Low to Address Hold
tEAH
10
—
ns
E3
ECLK Low to CS Valid (CS delay)
tECSD
—
140
ns
E4
ECLK Low to CS Hold
tECSH
10
—
ns
E5
CS Negated Width
tECSN
35
—
ns
E6
Read Data Setup Time
tEDSR
35
—
ns
E7
Read Data Hold Time
tEDHR
5
—
ns
E8
ECLK Low to Data High Impedance
tEDHZ
—
130
ns
E9
CS Negated to Data Hold (Read)
tECDH
0
—
ns
E10
CS Negated to Data High Impedance
tECDZ
—
1
tcyc
E11
ECLK Low to Data Valid (Write)
tEDDW
—
2
tcyc
E12
ECLK Low to Data Hold (Write)
tEDHW
10
—
ns
tEACC
450
—
ns
(Read)3
E13
Address Access Time
E14
Chip Select Access Time (Read)4
tEACS
380
—
ns
E15
Address Setup Time
tEAS
1/2
—
tcyc
NOTES:
1. All AC timing is shown with respect to 20% VDD and 70% VDD levels unless otherwise noted.
2. When the previous bus cycle is not an ECLK cycle, the address may be valid before ECLK goes low.
3. Address access time = tEcyc – tEAD – tEDSR.
4. Chip select access time = tEcyc – tECSD – tEDSR.
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CLKOUT
2A
3A
ECLK
1A
R/W
E1
E2
ADDR[23:0]
E3
E14
E6
CS
Freescale Semiconductor, Inc...
E5
E4
E15
E9
E13
DATA[15:0]
READ
WRITE
E7
E8
E11
DATA[15:0]
E10
WRITE
E12
68300 E CYCLE TIM
Figure 40 ECLK Timing Diagram
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MC68CK338
MC68CK338TS/D
Freescale Semiconductor, Inc.
Table 74 QSPI Timing
(VDD and VDDSYN = 2.7 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH 200 pF load on all QSPI pins)1
Freescale Semiconductor, Inc...
Num
Function
Symbol
Min
Max
Unit
fop
DC
DC
1/4
1/4
System Clock Frequency
System Clock Frequency
1
Operating Frequency
Master
Slave
2
Cycle Time
Master
Slave
tqcyc
4
4
510
—
tcyc
tcyc
3
Enable Lead Time
Master
Slave
tlead
2
2
128
—
tcyc
tcyc
4
Enable Lag Time
Master
Slave
tlag
—
2
1/2
—
SCK
tcyc
5
Clock (SCK) High or Low Time
Master
Slave2
tsw
2 tcyc – 60
2 tcyc – n
255 tcyc
—
ns
ns
6
Sequential Transfer Delay
Master
Slave (Does Not Require Deselect)
ttd
17
13
8192
—
tcyc
tcyc
7
Data Setup Time (Inputs)
Master
Slave
tsu
45
30
—
—
ns
ns
8
Data Hold Time (Inputs)
Master
Slave
thi
0
30
—
—
ns
ns
9
Slave Access Time
ta
—
1
tcyc
10
Slave MISO Disable Time
tdis
—
2
tcyc
11
Data Valid (after SCK Edge)
Master
Slave
tv
—
—
75
75
ns
ns
12
Data Hold Time (Outputs)
Master
Slave
tho
0
0
—
—
ns
ns
13
Rise Time
Input
Output
tri
tro
—
—
2
45
µs
ns
14
Fall Time
Input3
Output
tfi
tfo
—
—
2
45
µs
ns
NOTES:
1. All AC timing is shown with respect to 20% VDD and 70% VDD levels unless otherwise noted.
2. For high time, n = External SCK rise time; for low time, n = External SCK fall time.
3. Data can be recognized properly with longer transition times as long as MOSI/MISO signals from external
sources are at valid VOH/VOL prior to SCK transitioning between valid VOL and VOH. Due to process variation,
logic decision point voltages of the data and clock signals can differ, which can corrupt data if slower transition
times are used.
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3
2
PCS[3:0]
OUTPUT
5
13
12
SCK
CPOL=0
OUTPUT
4
1
SCK
CPOL=1
OUTPUT
6
12
4
13
7
Freescale Semiconductor, Inc...
MISO
INPUT
MSB IN
DATA
LSB IN
11
MOSI
OUTPUT
MSB OUT
PD
MSB IN
10
DATA
LSB OUT
PORT DATA
13
MSB OUT
12
QSPI MAST CPHA0
Figure 41 QSPI Timing — Master, CPHA = 0
3
2
PCS[3:0]
OUTPUT
5
13
12
1
SCK
CPOL=0
OUTPUT
4
1
7
SCK
CPOL=1
OUTPUT
12
4
13
6
MISO
INPUT
DATA
MSB IN
11
MOSI
OUTPUT
MSB OUT
PORT DATA
13
LSB IN
MSB
10
DATA
LSB OUT
PORT DATA
MSB
12
QSPI MAST CPHA1
Figure 42 QSPI Timing — Master, CPHA = 1
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MC68CK338
MC68CK338TS/D
Freescale Semiconductor, Inc.
3
2
SS
INPUT
5
13
12
SCK
CPOL=0
INPUT
4
1
SCK
CPOL=1
INPUT
12
4
Freescale Semiconductor, Inc...
MISO
OUTPUT
13
MSB OUT
11
10
11
8
DATA
9
LSB OUT
PD
MSB OUT
13
7
6
MOSI
INPUT
MSB IN
DATA
LSB IN
MSB IN
QSPI SLV CPHA0
Figure 43 QSPI Timing — Slave, CPHA = 0
SS
INPUT
5
1
13
4
12
SCK
CPOL=0
INPUT
4
2
3
SCK
CPOL=1
INPUT
12
13
10
10
8
MISO
OUTPUT
PD
MSB OUT
9
11
DATA
SLAVE
LSB OUT
PD
12
7
6
MOSI
INPUT
MSB IN
DATA
LSB IN
QSPI SLV CPHA1
Figure 44 QSPI Timing — Slave, CPHA = 1
MC68CK338
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