Fairchild ACE1502EM8 Arithmetic controller engine for low power application Datasheet

ACE1502 Product Family
Arithmetic Controller Engine (ACEx™)
for Low Power Applications
■ Hardware Bit–Coder (HBC)
■ On-chip oscillator
— No external components
— 1µs instruction cycle time +/-2% accuracy
■ Instruction set geared for block encryption
■ On-chip Power-on Reset
■ Programmable read and write disable functions
General Description
The ACE1502 (Arithmetic Controller Engine) family of microcontrollers is a dedicated programmable monolithic integrated circuit
for applications requiring high performance, low power, and small
size. It is a fully static part fabricated using CMOS technology.
The ACE1502 product family has an 8-bit microcontroller core,
64 bytes of RAM, 64 bytes of data EEPROM and 2K bytes of
code EEPROM. Its on-chip peripherals include a multifunction
16-bit timer, a watchdog/idle timer, and programmable undervoltage detection circuitry. On-chip clock and reset functions
reduce the number of required external components. The
ACE1502 product family is available in 8- and 14-pin SOIC,
TSSOP and DIP packages.
■
■
■
■
■
Features
■
■
■
■
■
■
■
Arithmetic Controller Engine
2K bytes on-board code EEPROM
64 bytes data EEPROM
64 bytes RAM
Watchdog
Multi-input wake-up on all eight general purpose I/O pins
16-bit multifunction timer with difference capture
■
■
■
■
■
■
Memory mapped I/O
32-level Low Voltage Detection
Brown-out Reset
Software selectable I/O option
— Push-pull outputs with tri-state option
— Weak pull-up or high impedance inputs
Fully static CMOS
— Low power HALT mode (100nA @ 2.7V)
— Power saving IDLE mode
Single supply operation
— 1.8-3.6V
40 years data retention
1.8V data EEPROM min writing voltage
1,000,000 data changes
8- and 14-pin SOIC, TSSOP and DIP packages
In-circuit programming
Block and Connection Diagram
VCC1
GND1
RESET2
Power-on Reset
(CKO) G0
Internal Oscillator
(CKI) G1
GPORT
ACE1502 core
G3
general
purpose
I/O with
multiinput
wakeup
(4 interrupt
sources
and vectors)
(TX) G5
HALT & IDLE Power
Saving Modes
12-bit Timer0 with
Watchdog Timer
(T1/TX) G2
G4
Brown-out Reset/Low
Battery Detect
16-bit Multi-function
Timer1 with Difference
Capture
Hardware Bit-Coder
G62
Programming Interface
64 bytes of RAM
G72
2K bytes of Code
EEPROM
64 bytes of Data
EEPROM
1. 100nf Decoupling capacitor recommended
2. Available only in the 14-pin package option
©2002 Fairchild Semiconductor Corporation
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
October 2002
VCC
Optional
LED
G4
VCC
G3
RF Interface
G0
G5
G1
RF Stage
G2
GND
Figure 3. ACE1502 8-pin SOIC and DIP Device Pinout
a) Normal Mode Operation
b) Programming Mode Operation
G3
1
8
VCC
LOAD
1
8
VCC
G4
2
7
GND
SFT_IN
2
7
GND
G5
G0
3
6
6
5
NC/VCC
NC
3
4
G2
G1
4
5
SFT_OUT
CKI
Figure 4. ACE1502 8-pin TSSOP Device Pinout
a) Normal Mode Operation
b) Programming Mode Operation
GND
1
8
G2
GND
1
8
SFT_OUT
VCC
2
7
G1
VCC
2
7
CKI
G3
G4
3
6
LOAD
3
6
NC
4
5
G0
G5
SFT_IN
4
5
NC/VCC
Figure 5. ACE1502 14-pin SOIC, TSSOP and DIP Device Pinout
a) Normal Mode Operation
b) Programming Mode Operation
G3
1
14
VCC
LOAD
1
14
VCC
G4
2
13
GND
13
3
12
3
12
GND
NC
4
11
NC
G2
SFT_IN
NC
2
NC
G6
NC
4
11
SFT_OUT
G7
G5
5
10
NC
NC
NC/VCC
5
10
NC
6
9
NC
7
8
G0
6
7
9
8
RESET
G1
2
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CKI
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Figure 2. ACEx Application Example (Remote Keyless Entry)
Absolute Maximum Ratings
Operating Conditions
Ambient Storage Temperature
Input Voltage
Lead Temperature (10s max)
Electrostatic Discharge on all pins
Relative Humidity (non-condensing)
95%
EEPROM write limits
See DC Electrical Characteristics
-65 °C to +150 °C
-0.3V to VCC + 0.3V
+300°C
2000V min
Part Number
Operating Voltage
ACE1502E
1.8 to 3.6V
-40°C to +85°C
ACE1502V
1.8 to 3.6V
-40°C to +125°C
Ambient Operating Temperature
ACE1502 DC Electrical Characteristics, VCC = 1.8 to 3.6V
All measurements are valid for ambient operating temperature unless otherwise stated.
Symbol
Parameter
Conditions
TYP
MAX
Units
0.4
0.4
0.5
0.6
0.6
0.6
0.7
1.0
mA
mA
mA
mA
2.7V @ 25°C
2.7V @ -40°C to +85°C
100
400
5000
nA
nA
3.6V @ 25°C
3.6V @ -40°C to +85°C
0.25
1000
10
nA
µA
1.8V
3.6V
210
250
400
µA
µA
3.3
Icc3
Suppy Current - no data EEPROM 1.8V
write in progress
2.2V
2.7V
3.6V
IccH
HALT Mode current
IccL4
VccW
IDLE Mode current
EEPROM write voltage
MIN
Code EEPROM in Programming Mode
3.0
3.6
V
Data EEPROM in Operating Mode
1.8
3.6
V
1µs/V
10ms/V
SVcc
Power Supply Slope
VIL
Input Low with Schmitt Trigger buffer
Vcc = 2.2 - 3.6V
VIH
Input High with Schmitt Trigger buffer
Vcc = 1.8 - 3.6V
IIP
Input Pull-up Current
Vcc = 3.6V, VIN = 0V
ITL
Tri-State Leakage
Vcc = 3.6V
VOL
Output Low Voltage:
G0, G1, G2, G3, G4, G5, G6, G7
0.2Vcc
Vcc < 2.2V
VOH
0.15Vcc
0.8Vcc
30
V
V
V
65
350
µA
2
200
nA
Vcc = 1.8 - 2.7V
2 mA sink
0.2Vcc
V
Output Low Voltage:
G0, G1, G2, G3, G4, G5, G6, G7
Vcc = 3.3 - 3.6V
7.0 mA sink
0.2Vcc
V
Output High Voltage:
G0, G1, G2, G3, G4, G5, G6, G7
Vcc = 2.2 - 2.7V
2 mA source
0.8Vcc
V
Output High Voltage:
G0, G1, G2, G3, G4, G5, G6, G7
Vcc = 3.3 - 3.6V
7 mA source
0.8Vcc
V
3. Icc active current is dependant on the program code.
4. Based on a continuous IDLE looping program.
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
2. Electrical Characteristics
All measurements are valid for ambient operating temperature unless otherwise stated.
Parameter
Conditions
MIN
TYP
MAX
Units
0.98
1.0
1.02
µs
Instruction cycle time from internal clock setpoint
3.3V at +25°C
Internal clock frequency variation
1.8V to 3.6V at constant temperature
1.8V to 3.6V at full temperature range (Note 6)
6
%
Crystal oscillator frequency
(Note 5)
25
MHz
External clock frequency
(Note 5)
8
MHz
10
ms
1.2
EEPROM write time
%
5.5
Internal clock start up time
(Note 6)
2
ms
Oscillator start up time
(Note 6)
2400
cycles
5. The maximum permissible frequency is guaranteed by design but is not 100% tested
6. The parameter is characterized but is not 100% tested, contact Fairchild for additional characterization data.
ACE1502 Electrical Characteristics for programming
All data valid at ambient temperature between 3.0V and 3.6V. The following characteristics are guaranteed
by design but are not 100% tested. See “EEPROM write time” in the AC Electrical Characteristics for
definition of the programming ready time.
Parameter
Description
MIN
MAX
Units
500
DC
ns
CLOCK low time
500
DC
SHIFT_IN setup time
100
tHI
CLOCK high time
tLO
tDIS
tDIH
SHIFT_IN hold time
100
ns
tDOS
SHIFT_OUT setup time
100
ns
tDOH
SHIFT_OUT hold time
900
TRESET
Power On Reset time
3.2
tLOAD1, tLOAD2, tLOAD3, tLOAD4
LOAD timing
ns
ns
ns
4.5
5
ms
µs
ACE1502 Low Battery Detect (LBD) Characteristics, Vcc = 1.8 to 3.6V
Parameter
Conditions
MIN
LBD voltage threshold variation
-40°C to +85°C
-5
TYP
MAX
Units
+5
%
ACE1502 Brown-out Reset (BOR) Characteristics, Vcc = 1.8 to 3.6V
Parameter
BOR voltage threshold variation
Conditions
MIN
TYP
MAX
Units
-40°C to +85°C
1.72
1.83
1.92
V
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
ACE1502 AC Electrical Characteristics, Vcc = 1.8 to 3.6V
ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
AC & DC Electrical Characteristic Graphs
The graphs in this section are for design guidance and are based on preliminary test data.
Figure 6. Internal Oscillator Frequency
Internal Oscillator Frequency vs. Temperature
2.01
2
Frequency (MHz)
1.99
3.6V
3.3V
2.8V
2.6V
2.2V
2.0V
1.8V
1.98
1.97
1.96
1.95
1.94
1.93
-40
0
25
85
125
Temperature [°C]
Figure 7. LBD and BOR Threshold Levels
LBD Levels 1,16 and 32
4.0
3.5
Voltage (V)
3.0
2.5
Level 1
Level 16
Level 32
2.0
1.5
1.0
0.5
0
-40
0
25
Temperature [°C]
85
125
BOR Level
1.840
1.835
Voltage (V)
1.830
1.825
1.820
BOR Level
1.815
1.810
1.805
1.800
-40
0
25
Temperature [°C]
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Figure 8. Icc Active
Icc Active (no data EEPROM writes) vs. Temperature
0.90
0.80
Current (mA)
0.70
0.60
4.0V
3.6V
2.7V
2.2V
1.8V
1.6V
0.50
0.40
0.30
0.20
0.10
0.00
-40
0
25
Temperature [°C]
85
125
Icc Active (data EEPROM writes) vs. Temperature
4.50
4.00
3.50
Current (mA)
3.00
4.0V
3.6V
2.7V
2.2V
1.8V
1.6V
2.50
2.00
1.50
1.00
0.50
0.00
-40
0
25
Temperature [°C]
85
125
Figure 9. HALT Mode Currents
HALT current vs. Temperature
20.000
18.000
16.000
Icc HALT (µA)
14.000
4.0V
3.6V
2.7V
2.2V
1.8V
1.6V
12.000
10.000
8.000
6.000
4.000
2.000
0.000
-40
0
25
85
125
Temperature [°C]
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Figure 10. IDLE Mode Currents
IDLE Mode Current
350.00
300.00
Icc IDLE [µA]
250.00
4.0V
3.6V
2.7V
2.2V
1.8V
1.6V
200.00
150.00
100.00
50.00
0.00
-40
0
25
85
125
Temperature [°C]
Figure 11. VOL/VOH vs. Current
VOL vs. IOL
3.00
2.50
VOL (V)
2.00
3.6V
4.0V
2.7V
2.2V
1.8V
1.50
1.00
0.50
0.00
0
2
5
7
9
12
15
IOL (mA)
VOH vs. IOH @ 25 °C
4.50
4.00
3.50
VOH (V)
3.00
4.0V
3.6V
2.7V
2.2V
1.8V
2.50
2.00
1.50
1.00
0.50
0.00
0
2
5
7
9
12
15
IOH current (mA)
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The ACEx microcontroller core is specifically designed for low
cost applications involving bit manipulation, shifting and block
encryption. It is based on a modified Harvard architecture
meaning peripheral, I/O, and RAM locations are addressed separately from instruction data.
the overall code efficiency of the ACEx microcontroller and
takes advantage of the flexibility found on Von Neumann style
machines.
The core differs from the traditional Harvard architecture by
aligning the data and instruction memory sequentially. This
allows the X-pointer (12-bits) to point to any memory location in
either segment of the memory map. This modification improves
The ACEx microcontroller has five general-purpose registers.
These registers are the Accumulator (A), X-Pointer (X), Program Counter (PC), Stack Pointer (SP), and Status Register
(SR). The X, SP, and SR registers are all memory-mapped.
3.1 CPU Registers
Figure 12. Programming Model
A
X
PC
SP
SR
7
11
10
3
0
8-bit accumulator register
0
12-bit X pointer register
0
11-bit program counter
0
4-bit stack pointer
R 0 0 G Z C H N
8-bit status register
NEGATIVE flag
HALF CARRY flag (from bit 3)
CARRY flag (from MSB)
ZERO flag (bit 4)
GLOBAL INTERRUPT enable
READY flag (from EEPROM)
3.1.1 Accumulator (A)
Bit 11 = 1, then the LD A, [00,X] instruction will take a value
from address range 0x800 to 0xFFF and load it into A.
The Accumulator is a general-purpose 8-bit register that is used
to hold data and results of arithmetic calculations or data manipulations.
The X register can also serve as a counter or temporary storage
register. However, this is true only for the 11-LSBs since the
12th bit is dedicated for memory space selection.
3.1.2 X-Pointer (X)
3.1.3 Program Counter (PC)
The X-Pointer register allows for a 12-bit indexing value to be
added to an 8-bit offset creating an effective address used for
reading and writing between the entire memory space. (Software can only read from code EEPROM.) This provides software with the flexibility of storing lookup tables in the code
EEPROM memory space for the core’s accessibility during normal operation.
The 11-bit program counter register contains the address of the
next instruction to be executed. After a reset, if in normal mode
the program counter is initialized to 0x800.
3.1.4 Stack Pointer (SP)
The ACEx microcontroller has an automatic program stack with
a 4-bit stack pointer. The stack can be initialized to any location
between addresses 0x30-0x3F. Normally, the stack pointer is
initialized by one of the first instructions in an application program. After a reset, the stack pointer is defaulted to 0xF pointing
to address 0x3F.
The ACEx core allows software to access the entire 12-bit XPointer register using the special X-pointer instructions e.g. LD
X, #000H. (See Table 8.) However, software may also access
the register through any of the memory-mapped instructions
using the XHI (X[11:8]) and XLO (X[7:0]) variables located at
0xBE and 0xBF, respectively. (See Table 10.)
The stack is configured as a data structure which decrements
from high to low memory. Each time a new address is pushed
onto the stack, the core decrements the stack pointer by two.
Each time an address is pulled from the stack, the core increments the stack pointer is by two. At any given time, the stack
pointer points to the next free location in the stack.
The X register is divided into two sections. The 11 least significant bits (LSBs) of the register is the address of the program or
data memory space. The most significant bit (MSB) of the register is write only and selects between the data (0x000 to
0x0FF) or program (0x800 to 0xFFF) memory space.
When a subroutine is called by a jump to subroutine (JSR)
instruction, the address of the instruction is automatically
pushed onto the stack least significant byte first. When the
Example: If Bit 11 = 0, then the LD A, [00,X] instruction will take
a value from address range 0x000 to 0x0FF and load it into A. If
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
3. Arithmetic Controller Core
3.1.5 Status Register (SR)
The 8-bit Status register (SR) contains four condition code indicators (C, H, Z, and N), one interrupt masking bit (G), and an
EEPROM write flag (R.) The condition codes are automatically
updated by most instructions. (See Table 9.)
3.2 Interrupt handling
When an interrupt is recognized, the current instruction completes its execution. The return address (the current value in the
program counter) is pushed onto the stack and execution continues at the address specified by the unique interrupt vector
(see Table 10.). This process takes five instruction cycles. At
the end of the interrupt service routine, a return from interrupt
(RETI) instruction is executed. The RETI instruction causes the
saved address to be pulled off the stack in reverse order. The G
bit is set and instruction execution resumes at the return
address.
Carry/Borrow (C)
The carry flag is set if the arithmetic logic unit (ALU) performs a
carry or borrow during an arithmetic operation and by its dedicated instructions. The rotate instruction operates with and
through the carry bit to facilitate multiple-word shift operations.
The LDC and INVC instructions facilitate direct bit manipulation
using the carry flag.
The ACEx microcontroller is capable of supporting four interrupts. Three are maskable through the G bit of the SR and the
fourth (software interrupt) is not inhibited by the G bit (Figure
13.) The software interrupt is generated by the execution of the
INTR instruction. Once the INTR instruction is executed, the
ACEx core will interrupt whether the G bit is set or not. The
INTR interrupt is executed in the same manner as the other
maskable interrupts where the program counter register is
stacked and the G bit is cleared. This means, if the G bit was
enabled prior to the software interrupt the RETI instruction must
be used to return from interrupt in order to restore the G bit to its
previous state. However, if the G bit was not enabled prior to
the software interrupt the RET instruction must be used.
Half Carry (H)
The half carry flag indicates whether an overflow has taken
place on the boundary between the two nibbles in the accumulator. It is primarily used for Binary Coded Decimal (BCD) arithmetic calculation.
Zero (Z)
The zero flag is set if the result of an arithmetic, logic, or data
manipulation operation is zero. Otherwise, it is cleared.
Negative (N)
The negative flag is set if the MSB of the result from an arithmetic, logic, or data manipulation operation is set to one. Otherwise, the flag is cleared. A result is said to be negative if its MSB
is a one.
In case of multiple interrupts occurring at the same time, the
ACEx microcontroller core has prioritized the interrupts. The
interrupt priority sequence in shown in Table 7.
Interrupt Mask (G)
Table 7: Interrupt Priority Sequence
The interrupt request mask (G) is a global mask that disables all
maskable interrupt sources. If the G Bit is cleared, interrupts
can become pending, but the operation of the core continues
uninterrupted. However, if the G Bit is set an interrupt is recognized. After any reset, the G bit is cleared by default and can
only be set by a software instruction. When an interrupt is recognized, the G bit is cleared after the PC is stacked and the
interrupt vector is fetched. Once the interrupt is serviced, a
Priority (4 highest, 1 lowest)
Interrupt
4
MIW (EDGEI)
3
Timer0 (TMRI0)
2
Timer1 (TMRI1)
1
Software (INTR)
Interrupt Source with Priority
Figure 13. Basic Interrupt Structure
INTR
T1
T1PND
T0
T0PND
MIW
WKPND
Interrupt
Pending
Flags
Interrupt
T1EN
T0INT
EN
WKINT
EN
G
Global Interrupt
Enable
Interrupt Enable Bits
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
return from interrupt instruction is normally executed to restore
the PC to the value that was present before the interrupt
occurred. The G bit is the reset to one after a return from interrupt is executed. Although the G bit can be set within an interrupt service routine, “nesting” interrupts in this way should only
be done when there is a clear understanding of latency and of
the arbitration mechanism.
subroutine is finished, a return from subroutine (RET)
instruction is executed. The RET instruction pulls the previously
stacked return address from the stack and loads it into the
program counter. Execution then continues at the recovered
return address.
Immediate
The ACEx microcontroller has seven addressing modes
indexed, indirect, direct, immediate, absolute jump, and relative
jump.
The instruction contains an 8-bit immediate field as an operand.
Indexed
This instruction has no operands associated with it.
Inherent
Absolute
The instruction allows an 8-bit unsigned offset value to be
added to the 11-LSBs of the X-pointer yielding a new effective
address. This mode can be used to address either data or program memory space.
The instruction contains an 11-bit address that directly points to
a location in the program memory space. There are two operands associated with this addressing mode. Each operand contains a byte of an address. This mode is used only for the long
jump (JMP) and JSR instructions.
Indirect
The instruction allows the X-pointer to address any location
within the data memory space.
Relative
This mode is used for the short jump (JP) instructions where the
operand is a value relative to the current PC address. With this
instruction, software is limited to the number of bytes it can
jump, -31 or +32.
Direct
The instruction contains an 8-bit address field that directly
points to the data memory space as an operand.
Table 8. Instruction Addressing Modes
Instruction
Immediate
Direct
Indexed
Indirect
A, #
A, #
A, #
A, #
A, #
A, #
A, M
A, M
A, M
A, M
A, M
A, M
A, [#, X]
A, [#, X]
A, [#, X]
A, [#, X]
A, [#, X]
A, [#, X]
A, [X]
A, [X]
A, [X]
A, [X]
A, [X]
A, [X]
ADC
ADD
AND
OR
SUBC
XOR
CLR
INC
DEC
IFEQ
IFGT
IFNE
IFLT
M
M
M
A, #
A, #
A, #
X, #
X, #
X, #
X, #
M,#
M,#
A
A
A
A, M
A, M
A, M
SC
RC
IFC
IFNC
INVC
LDC
STC
#, M
#, M
RLC
RRC
M
M
LD
ST
Inherent
A, [#, X]
A, [#, X]
A, [#, X]
Relative
Absolute
X
X
X
A, [X]
A, [X]
A, [X]
no-op
no-op
no-op
no-op
no-op
A, #
M, #
X, #
A, M
A, M
A
A
M, M
A, [#, X]
A, [#, X]
A, [X]
A, [X]
NOP
no-op
IFBIT
#, A
#, M
[#, X]
IFNBIT
SBIT
RBIT
#, A
#, M
#, M
#, M
[#, X]
[#, X]
[#, X]
JP
JSR
JMP
RET
RETI
INTR
Rel
[#, X]
[#, X]
no-op
no-op
no-op
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
3.3 Addressing Modes
Mnemonic
Operand
Bytes
Cycles
Flags
affected
Mnemonic
Operand
Bytes
Cycles
X
Flags
affected
ADC
A, [X]
1
1
C,H,Z,N
INC
1
1
Z
ADC
A, [#,X]
2
3
C,H,Z,N
INTR
1
5
None
ADC
A, M
2
2
C,H,Z,N
INVC
1
1
C
ADC
A, #
2
2
C,H,Z,N
JMP
M
3
4
None
ADD
A, [X]
1
1
Z,N
JMP
[#, X]
2
3
None
ADD
A, [#,X]
2
3
Z,N
JP
1
1
None
ADD
A, M
2
2
Z,N
JSR
M
3
5
None
None
ADD
A, #
2
2
Z,N
JSR
[#, X]
2
5
AND
A, [X]
1
1
Z,N
LD
A, #
2
2
None
AND
A, [#,X]
2
3
Z,N
LD
A, [#,X]
2
3
None
AND
A, M
2
2
Z,N
LD
A, [X]
1
1
None
AND
A, #
2
2
Z,N
LD
A, M
2
2
None
CLR
X
1
1
Z
LD
M, #
3
3
None
CLR
A
1
1
C,H,Z,N
LD
M, M
3
3
None
CLR
M
2
1
C,H,Z,N
LD
X, #
3
3
None
DEC
X
1
1
Z
LDC
#, M
2
2
C
DEC
A
1
1
Z,N
NOP
1
1
None
DEC
M
2
2
Z,N
OR
A, [X]
1
1
Z, N
IFBIT
#, A
1
1
None
OR
A, [#,X]
2
3
Z,N
Z,N
IFBIT
#, M
2
2
None
OR
A, M
2
2
IFBIT
#, [X]
1
1
None
OR
A, #
2
2
Z,N
1
1
None
RBIT
#, [X]
1
2
Z,N
#, M
2
2
Z,N
IFC
IFEQ
A, [#, X]
2
3
None
RBIT
IFEQ
A, [X]
1
1
None
RC
1
1
C,H
IFEQ
A, #
2
2
None
RET
1
5
None
IFEQ
A, M
2
2
None
RETI
IFEQ
M, #
3
3
None
RLC
A
1
5
None
1
1
C,Z,N
IFEQ
X, #
3
3
None
RLC
M
2
2
C,Z,N
IFGT
A, [#, X]
2
3
None
RRC
A
1
1
C,Z,N
IFGT
A, [X]
1
1
None
RRC
M
2
2
C,Z,N
IFGT
A, #
2
2
None
SBIT
#, [X]
1
2
Z,N
IFGT
A, M
2
2
None
SBIT
#, M
2
2
Z,N
IFGT
X, #
3
3
None
SC
1
1
C,H
IFLT
X, #
3
3
None
ST
A, [#,X]
2
3
None
IFNBIT
#, A
1
1
None
ST
A, [X]
1
1
None
None
IFNBIT
#, M
2
2
None
ST
A, M
2
2
IFNBIT
#, [X]
1
1
None
STC
#, M
2
2
Z,N
1
1
None
SUBC
A, [X]
1
1
C,H,Z,N
IFNC
IFNE
A, [#, X]
2
3
None
SUBC
A, [#,X]
2
3
C,H,Z,N
IFNE
A, [X]
1
1
None
SUBC
A, M
2
2
C,H,Z,N
IFNE
A, #
2
2
None
SUBC
A, #
2
2
C,H,Z,N
IFNE
A, M
2
2
None
XOR
A, [X]
1
1
Z,N
IFNE
X, #
3
3
None
XOR
A, [#,X]
2
3
Z,N
IFNE
M, #
3
3
None
XOR
A, M
2
2
Z,N
INC
A
1
1
Z,N
XOR
A, #
2
2
Z,N
INC
M
2
2
Z,N
11
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Table 9. Instruction Cycles and Bytes
All I/O ports, peripheral registers, and core registers (except the accumulator and the program counter) are mapped into the memory
space.
Table 10. Memory Mapped Registers
Address
Memory Space
Block
Contents
0x00 - 0x3F
Data
SRAM
0x40 - 0x7F
Data
EEPROM
0x80-0x9F
Data
Reserved
0xA0
Data
HBC
HBCNTRL register
0xA1
Data
HBC
PSCALE register
0xA2
Data
HBC
HPATTERN register
0xA3
Data
HBC
LPATTERN register
0xA4
Data
HBC
BPSEL register
0xA7
Data
Timer1
T1RBLO register
0xA8
Data
Timer1
T1RBHI register
Data RAM
Data EEPROM
0xA9
Data
HBC
0xAA
Data
Timer1
DAT0 register
T1RALO register
0xAB
Data
Timer1
T1RAHI register
0xAC
Data
Timer1
TMR1LO register
0xAD
Data
Timer1
TMR1HI register
0xAE
Data
Timer1
T1CNTRL register
0xAF
Data
MIW
WKEDG register
0xB0
Data
MIW
WKPND register
0xB1
Data
MIW
WKEN register
0xB2
Data
I/O
PORTGD register
0xB3
Data
I/O
PORTGC register
0xB4
Data
I/O
PORTGP register
0xB5
Data
Timer0
WDSVR register
0xB6
Data
Timer0
T0CNTRL register
0xB7
Data
Clock
0xB8-0xBA
Data
Reserved
HALT mode register
0xBB
Data
Init. Register
Initialization Register 1
0xBC
Data
Init. Register
Initialization Register 2
0xBD
Data
LBD
LBD register
0xBE
Data
Core
XHI register
0xBF
Data
Core
XLO register
0xC0
Data
Clock
Power Mode Clear (PMC) Register
0xCE
Data
Core
SP register
0xCF
Data
Core
Status register (SR)
0xD0 - 0xFF
Data
Reserved
0x800 - 0xFF5
Program
EEPROM
0xFF6 - 0xFF7
Program
Core
Timer0 Interrupt vector
0xFF8 - 0xFF9
Program
Core
Timer1 Interrupt vector
Code EEPROM
0xFFA - 0xFFB
Program
Core
MIW Interrupt vector
0xFFC - 0xFFD
Program
Core
Soft Interrupt vector
0xFFE - 0xFFF
Program
Reserved
12
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
3.4 Memory Map
read, write, or enter HALT/IDLE mode while the data EEPROM
is busy (R = 0) can affect the current data being written.
The ACEx microcontroller has 64 bytes of SRAM and 64 bytes
of EEPROM available for data storage. The device also has 2K
bytes of EEPROM for program storage. Software can read and
write to SRAM and data EEPROM but can only read from the
code EEPROM. While in normal mode, the code EEPROM is
protected from any writes. The code EEPROM can only be
rewritten when the device is in program mode and if the write
disable (WDIS) bit of the initialization register is not set to 1.
3.6 Initialization Registers
The ACEx microcontroller has two 8-bit wide initialization
registers. These registers are read from the memory space on
power-up to initialize certain on-chip peripherals. Figure 14
provides a detailed description of Initialization Register 1. The
Initialization Register 2 is used to trim the internal oscillator to
its appropriate frequency. This register is pre-programmed in
the factory to yield an internal instruction clock of 1MHz.
While in normal mode, the user can write to the data EEPROM
array by 1) polling the ready (R) flag of the SR, then 2) executing the appropriate instruction. If the R flag is 1, the data
EEPROM block is ready to perform the next write. If the R flag is
0, the data EEPROM is busy. The data EEPROM array will
reset the R flag after the completion of a write cycle. Attempts to
The Initialization Registers 1 and 2 can be read from and written
to during programming mode. However, re-trimming the internal oscillator (writing to the Initialization Register 2) once it has
left the factory is discouraged.
Figure 14. Initialization Register 1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CMODE[0]
CMODE[1]
WDEN
BOREN
LDBEN
UBD
WDIS
RDIS
(0) RDIS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
WDIS
UBD
LBDEN
BOREN
WDEN
CMODE[1]
CMODE[0]
If set, disables attempts to read the contents from the memory while in programming mode. Once this bit is
set, it is no longer possible to unset this option even though the write disable option is not enabled.
If set, disables attempts to write new contents to the memory while in programming mode
If set, the device will not allow any writes to occur in the upper block of data EEPROM (0x60-0x7F)
If set, the Low Battery Detection circuit is enabled
If set, allows a BOR to occur if Vcc falls below the voltage reference level
If set, enables the on-chip processor watchdog circuit
Clock mode select bit 1 (See Table 16)
Clock mode select bit 0 (See Table 16)
4. Timer 1
Timer 1 is a versatile 16-bit timer that can operate in one of four
modes:
The timer can be started or stopped through the T1CNTRL register bit T1C0. When running, the timer counts down (decrements) every clock cycle. Depending on the operating mode,
the timer’s clock is either the instruction clock or a transition on
the T1 input. In addition, occurrences of timer underflow (transitions from 0x0000 to 0xFFFF/T1RA/T1RB value) can either
generate an interrupt and/or toggle the T1 output pin.
• Pulse Width Modulation (PWM) mode, which generates
pulses of a specified width and duty cycle
• External Event Counter mode, which counts occurrences of
an external event
• Standard Input Capture mode, which measures the elapsed
time between occurrences of external events
Timer 1’s interrupt (TMRI1) can be enabled by interrupt enable
(T1EN) bit in the T1CNTRL register. When the timer interrupt is
enabled, depending on the operating mode, the source of the
interrupt is a timer underflow and/or a timer capture.
• Difference Input Capture mode, which automatically measures the difference between edges.
Timer 1 contains a 16-bit timer/counter register (TMR1), a 16-bit
auto-reload/capture register (T1RA), a secondary 16-bit autoreload register (T1RB), and an 8-bit control register
(T1CNTRL). All register are memory-mapped for simple access
through the core with both the 16-bit registers organized as a
pair of 8-bit register bytes {TMR1HI, TMR1LO}, {T1RAHI,
T1RALO}, and {T1RBHI, T1RBLO}. Depending on the operating
mode, the timer contains an external input or output (T1) that is
multiplexed with the I/O pin G2. By default, the TMR1 is reset to
0xFFFF, T1RA/T1RB is reset to 0x0000, and T1CNTRL is reset
to 0x00.
4.1 Timer control bits
Reading and writing to the T1CNTRL register controls the
timer’s operation. By writing to the control bits, the user can
enable or disable the timer interrupts, set the mode of operation,
and start or stop the timer. The T1CNTRL register bits are
described in Table 11 and Table 12.
13
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3.5 Memory
T1CNTRL Register
Bit Name
Function
Bit 7
T1C3
Timer TIMER1 control bit 3 (see Table 12)
Bit 6
T1C2
Timer TIMER1 control bit 2 (see Table 12)
Bit 5
T1C1
Timer TIMER1 control bit 1 (see Table 12)
Bit 4
T1C0
Timer TIMER1 run: 1= Start timer, 0 = Stop timer;
or Timer TIMER1 underflow interrrupt pending flag in input capture mode
Bit 3
T1PND
Bit 2
T1EN
Timer1 interrupt enable bit: 1 = Timer1 interrupt enabled,
0 = Timer1 interrupt disabled
Bit 1
M1S1
Capture type: 0 = Pulse capture, 1 = Cycle capture (see Table 12)
Bit 0
T1RBEN
Timer1 interrupt pending flag: 1 = Timer1 interrupt
Pending, 0 = Timer1 interrupt not pending
PWM Mode: 0 = Timer1 reload on T1RA, 1 = TIMER1 reload on T1RA and T1RB
(always starting with T1RA)
Table 12. Timer 1 Operating Modes
T1
C3
T1
C2
T1
C1
M4
S1
T1
RB
0
0
0
X
X
MODE 2
TIMER1 Underflow
T1 Pos. Edge
0
0
1
X
X
MODE 2
TIMER1 Underflow
T1 Neg. Edge
1
0
1
X
0
MODE 1 T1 Toggle
Autoreload T1RA
Instruction Clock
1
0
0
X
0
MODE 1 No T1 Toggle
Autoreload T1RA
Instruction Clock
1
0
1
X
1
MODE 1 T1 Toggle
Autoreload T1RA/T1RB
Instruction Clock
1
0
0
X
1
MODE 1 No T1 Toggle
Autoreload T1RA/T1RB
Instruction Clock
0
1
0
X
X
MODE 3 Captures:
T1 Pos Edge
Pos. T1 Edge
Instruction Clock
0
1
1
X
X
MODE 3 Captures:
T1 Neg Edge
Neg. T1 Edge
Instruction Clock
1
1
0
0
X
MODE 4
Pos. to Neg.
Instruction Clock
1
1
0
1
X
MODE 4
Pos. to Pos.
Instruction Clock
1
1
1
0
X
MODE 4
Neg. to Pos.
Instruction Clock
1
1
1
1
X
MODE 4
Neg. to Neg.
Instruction Clock
Timer Mode Source
Interrupt
Timer Counts-on
4.2 Mode 1: Pulse Width Modulation (PWM) Mode
In the PWM mode, the timer counts down at the instruction
clock rate. When an underflow occurs, the timer register is
reloaded from T1RA/T1RB and the count down proceeds from
the loaded value. At every underflow, a pending flag (T1PND)
located in the T1CNTRL register is set. Software must then
clear the T1PND flag and load the T1RA/T1RB register with an
alternate PWM value (if desired.) In addition, the timer can be
configured to toggle the T1 output bit upon underflow. Configuring the timer to toggle T1 results in the generation of a signal
outputted from port G2 with the width and duty cycle controlled
by the values stored in the T1RA/T1RB. A block diagram of the
timer’s PWM mode of operation is shown in Figure 15.
the T1RA and T1RB registers. A hardware select logic is implemented to select between T1RA and T1RB alternately, always
starting with T1RA, every timer underflows to auto-reload the
timer registers. This feature is useful when a signal with variable
duty cycle needs to be generated without software intervention.
The timer has one interrupt (TMRI1) that is maskable through
the T1EN bit of the T1CNTRL register. However, the core is only
interrupted if the T1EN bit and the G (Global Interrupt enable)
bit of the SR is set. If interrupts are enabled, the timer will generate an interrupt each time T1PND flags is set (whenever the
timer underflows provided that the pending flag was cleared.)
The interrupt service routine is responsible for proper handling
of the T1PND flag and the T1EN bit.
The PWM timer can be configured to use the T1RA register only
for auto-reloading the timer registers or can be configured to
use both T1RA and T1RB alternately. If the T1RBEN bit of the
T1CNTRL register is 0, the PWM timer will reload using only
T1RA ignoring any value store in the T1RB register. However, if
the T1RBEN bit is 1 the PWM timer will be reloaded using both
The interrupt will be synchronous with every rising and falling
edge of the T1 output signal. Generating interrupts only on rising or falling edges of T1 is achievable through appropriate handling of the T1EN bit or T1PND flag through software.
14
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Table 11. Timer 1 Control Register (T1CNTRL)
4.3 Mode 2: External Event Counter Mode
1. Configure T1 as an output by setting bit 2 of PORTGC.
- SBIT 2, PORTGC
; Configure G2 as an output
The T1 input should be connected to an external device that
generates a positive/negative-going pulse for each event. By
clocking the timer through T1, the number of positive/negative
transitions can be counted therefore allowing software to capture the number of events that occur. The input signal on T1
must have a pulse width equal to or greater than one instruction
clock cycle.
The External Event Counter mode operates similarly to the
PWM mode; however, the timer is not clocked by the instruction
clock but by transitions of the T1 input signal. The edge is
selectable through the T1C1 bit of the T1CNTRL register. A
block diagram of the timer’s External Event Counter mode of
operation is shown in Figure 16.
2. Initialize T1 to 1 (or 0) by setting (or clearing) bit 2 of
PORTGD.
- SBIT 2, PORTGD
; Set G2 high
3. Load the initial PWM high (low) time into the timer register.
- LD TMR1LO, #6FH
; High (Low) for 1.391ms
(1MHz clock)
- LD
TMR1HI, #05H
The counter can be configured to sense either positive-going or
negative-going transitions on the T1 pin. The maximum frequency at which transitions can be sensed is one-half the frequency of the instruction clock.
4. Load the PWM low (high) time into the T1RA register.
- LD T1RALO, #2FH
; Low (High) for .303ms
(1MHz clock)
- LD T1RAHI, #01H
As with the PWM mode, when the counter underflows the
counter is reloaded from the T1RA register and the count down
proceeds from the loaded value. At every underflow, a pending
flag (T1PND) located in the T1CNTRL register is set. Software
must then clear the T1PND flag and can then load the T1RA
register with an alternate value.
5. Write the appropriate control value to the T1CNTRL register
to select PWM mode with T1 toggle, to clear the enable bit
and pending flag, and to start the timer. (See Table 11 and
Table 12.)
- LD T1CNTRL, #0B0H ; Setting the T1C0 bit starts the
timer
The counter has one interrupt (TMRI1) that is maskable through
the T1EN bit of the T1CNTRL register. However, the core is only
interrupted if the T1EN bit and the G (Global Interrupt enable)
bit of the SR is set. If interrupts are enabled, the counter will
generate an interrupt each time the T1PND flag is set (whenever timer underflows provided that the pending flag was
cleared.) The interrupt service routine is responsible for proper
handling of the T1PND flag and the T1EN bit.
6. After every underflow, load T1RA with alternate values. If the
user wishes to generate an interrupt on a T1 output transition, reset the pending flags and then enable the interrupt
using T1EN. The G bit must also be set. The interrupt
service routine must reset the pending flag and perform
whatever processing is desired.
- RBIT T1PND, T1CNTRL ; T1PND equals 3
- LD T1RALO, #6FH
; High (Low) for 1.391ms
(1MHz clock)
- LD T1RAHI, #05H
The following steps show how to properly configure Timer 1 to
operate in the External Event Counter mode. For this example,
the counter is clocked every falling edge of the T1 input signal.
Follow the instructions in parentheses to clock the counter every
rising edge.
1. Configure T1 as an input by clearing bit 2 of PORTGC.
- RBIT
2, PORTGC
; Configure G2 as an input
Figure 15. Pulse Width Modulation Mode
2. Initialize T1 to input with pull-up by setting bit 2 of PORTGD.
- SBIT
2, PORTGD
; Set G2 high
16-bit Auto-Reload
Register (T1RA)
3. Enable the global interrupt enable bit.
- SBIT
4, STATUS
0
S 1
4. Load the initial count into the TMR1 and T1RA registers.
When the number of external events is detected, the counter
will reach zero; however, it will not underflow until the next
event is detected. To count N pulses, load the value N-1 into
the registers. If it is only necessary to count the number of
occurrences and no action needs to be taken at a particular
count, load the value 0xFFFF into the registers.
- LD
TMR1LO, #0FFH
- LD
TMR1HI, #0FFH
- LD
T1RALO, #0FFH
- LD
T1RAHI, #0FFH
16-bit Auto-Reload
Register (T1RB)
Data
Bus
T1RBEN
T1
Reload select logic
Data
Latch
Underflow
Interrupt
16-bit Timer (TMR1)
Instruction
Clock
15
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
The following steps show how to properly configure Timer 1 to
operate in the PWM mode. For this example, the T1 output signal is toggled with every timer underflow and the “high” and
“low” times for the T1 output can be set to different values. The
T1 output signal can start out either high or low depending on
the configuration of G2; the instructions below are for starting
with the T1 output high. Follow the instructions in parentheses
to start the T1 output low.
For this operating mode, the T1C0 control bit serves as the
timer underflow interrupt pending flag. The Timer 1 interrupt service routine must read both the T1PND and T1C0 flags to determine the cause of the interrupt. A set T1C0 flag means that a
timer underflow occurred whereas a set T1PND flag means that
a capture occurred in T1RA. It is possible that both flags will be
found set, meaning that both events occurred at the same time.
The interrupt service routine should take this possibility into
consideration.
6. When the counter underflows, the interrupt service routine
must clear the T1PND flag and take whatever action is
required once the number of events occurs. If the software
wishes to merely count the number of events and the anticipated number may exceed 65,536, the interrupt service
routine should record the number of underflows by incrementing a counter in memory. Software can then calculate
the correct event count.
- RBIT T1PND, T1CNTRL ; T1PND equals 3
Because the T1C0 bit is used as the underflow interrupt pending flag, it is not available for use as a start/stop bit as in the
other modes.
The TMR1 register counts down continuously at the instruction
clock rate starting from the time that the input capture mode is
selected. (See Table 11 and Table 12) To stop the timer from
running, you must change the mode to an alternate mode
(PWM or External Event Counter) while resetting the T1C0 bit.
Figure 16. External Event Counter Mode
The input pins can be independently configured to sense positive-going or negative-going transitions. The edge sensitivity of
pin T1 is controlled by bit T1C1 as indicated in Table 12.
16-bit Auto-Reload
Register (T1RA)
Data
Bus
Underflow
Interrupt
The edge sensitivity of a pin can be changed without leaving the
input capture mode even while the timer is running. This feature
allows you to measure the width of a pulse received on an input
pin.
16-bit Counter (TMR1)
For example, the T1 pin can be programmed to be sensitive to a
positive-going edge. When the positive edge is sensed, the
TMR1 register contents is transferred to the T1RA register and
a Timer 1 interrupt is generated. The Timer 1 interrupt service
routine records the contents of the T1RA register, changes the
edge sensitivity from positive to negative-going edge, and
clears the T1PND flag. When the negative-going edge is sensed
another Timer 1 interrupt is generated. The interrupt service
routine reads the T1RA register again. The difference between
the previous reading and the current reading reflects the
elapsed time between the positive edge and negative edge of
the T1 input signal i.e. the width of the positive-going pulse.
T1
Edge Selector
Logic
4.4 Mode 3: Input Capture Mode
In the Input Capture mode, the timer is used to measure
elapsed time between edges of an input signal. Once the timer
is configured for this mode, the timer starts counting down
immediately at the instruction clock rate. The Timer 1 will then
transfer the current value of the TMR1 register into the T1RA
register as soon as the selected edge of T1 is sensed. The input
signal on T1 must have a pulse width equal to or greater than
one instruction clock cycle. At every T1RA capture, software
can then store the values into RAM to calculate the elapsed
time between edges on T1. At any given time (with proper consideration of the state of T1) the timer can be configured to capture on positive-going or negative-going edges. A block diagram
of the timer’s Input Capture mode of operation is shown in Figure 17.
Remember that the Timer1 interrupt service routine must test
the T1C0 and T1PND flags to determine the cause of the interrupt. If the T1C0 flag caused the interrupt, the interrupt service
routine should record the occurrence of an underflow by incrementing a counter in memory or by some other means. The
software that calculates the elapsed time between captures
should take into account the number of underflow that occurred
when making its calculation.
The following steps show how to properly configure Timer 1 to
operate in the Input Capture mode.
1. Configure T1 as an input by clearing bit 2 of PORTGC.
- RBIT 2, PORTGC
; Configure G2 as an input
The timer has one interrupt (TMRI1) that is maskable through
the T1EN bit of the T1CNTRL register. However, the core is only
interrupted if the T1EN bit and the G (Global Interrupt enable)
bit of the SR is set. The Input Capture mode contains two interrupt pending flags 1) the TMR1 register capture in T1RA
(T1PND) and 2) timer underflow (T1C0). If interrupts are
enabled, the timer will generate an interrupt each time a pending flag is set (provided that the pending flag was previously
cleared.) The interrupt service routine is responsible for proper
handling of the T1PND flag, T1C0 flag, and the T1EN bit.
2. Initialize T1 to input with pull-up by setting bit 2 of PORTGD.
- SBIT 2, PORTGD
; Set G2 high
3. Enable the global interrupt enable bit.
- SBIT 4, STATUS
4. With the timer stopped, load the initial time into the TMR1
register (typically the value is 0xFFFF.)
- LD TMR1LO, #0FFH
- LD TMR1HI, #0FFH
5. Write the appropriate control value to the T1CNTRL register
to select Input Capture mode, to sense the appropriate
edge, to set the enable bit, and to clear the pending flags.
16
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
5. Write the appropriate control value to the T1CNTRL register
to select External Event Counter mode, to clock every falling
edge, to set the enable bit, to clear the pending flag, and to
start the counter. (See Table 11 and Table 12 )
- LD T1CNTRL, #34H (#00h) ;Setting the T1C0 bit starts
the timer
the standard Input Capture mode both the capture (T1PND) and
the underflow (T1C0) flags must be monitored and handled
appropriately. This feature allows the ACEx microcontroller to
capture very small pulses where standard microcontrollers
might have missed cycles due to the limited bandwidth.
6. As soon as the input capture mode is enabled, the timer
starts counting. When the selected edge is sensed on T1,
the T1RA register is loaded and a Timer 1 interrupt is
triggered.
Figure 18. Difference Capture Mode
Figure 17. Input Capture Mode
Capture
Interrupt
Capture
Interrupt
16-bit Input Capture
Register (T1RA)
T1
Edge Selector
Logic
Difference
Logic
T1
Data
Bus
Edge Selector
Logic
Data
Bus
Underflow
Interrupt
16-bit Input Capture
Register (T1RA)
16-bit Timer (TMR1)
Underflow
Interrupt
16-bit Timer (TMR1)
Instruction
Clock
Instruction
Clock
4.5 Mode 4: Difference Input Capture Mode
The Difference Input Capture mode works similarly to the standard Input Capture mode. However, for the Difference Input
Capture the timer automatically captures the elapsed time
between the selected edges without the core needing to perform the calculation.
5. Timer 0
Timer 0 is a 12-bit free running idle timer. Upon power-up or any
reset, the timer is reset to 0x000 and then counts up continuously based on the instruction clock of 1MHz (1 µs). Software
cannot read from or write to this timer. However, software can
monitor the timer's pending (T0PND) bit that is set every 8192
cycles (initially 4096 cycles after a reset). The T0PND flag is set
every other time the timer overflows (transitions from 0xFFF to
0x000) through a divide-by-2 circuit. After an overflow, the timer
will reset and restart its counting sequence.
For example, the standard Input Capture mode requires that the
timer be configured to capture a particular edge (rising or falling) at which time the timer’s value is copied into the capture
register. If the elapsed time is required, software must move the
captured data into RAM and reconfigure the Input Capture
mode to capture on the next edge (rising or falling). Software
must then subtract the difference between the two edges to
yield useful information.
Software can either poll the T0PND bit or vector to an interrupt
subroutine. In order to interrupt on a T0PND, software must be
sure to enable the Timer 0 interrupt enable (T0INTEN) bit in the
Timer 0 control (T0CNTRL) register and also make sure the G
bit is set in SR. Once the timer interrupt is serviced, software
should reset the T0PND bit before exiting the routine. Timer 0
supports the following functions:
The Difference Capture mode eliminates the need for software
intervention and allows for capturing very short pulse or cycle
widths. It can be configured to capture the elapsed time
between:
1. rising edge to falling edge
1. Exiting from IDLE mode (See Section 16 for details.)
2. rising edge to rising edge
2. Start up delay from HALT mode
3. falling edge to rising edge
3. Watchdog pre-scalar (See Section 6 for details.)
4. falling edge to falling edge
The T0INTEN bit is a read/write bit. If set to 0, interrupt requests
from the Timer 0 are ignored. If set to 1, interrupt requests are
accepted. Upon reset, the T0INTEN bit is reset to 0.
Once configured, the Difference Capture timer waits for the first
selected edge. When the edge transition has occurred, the 16bit timer starts counting up based every instruction clock cycle.
It will continue to count until the second selected edge transition
occurs at which time the timer stops and stores the elapse time
into the T1RA register.
The T0PND bit is a read/write bit. If set to 1, it indicates that a
Timer 0 interrupt is pending. This bit is set by a Timer 0 overflow
and is reset by software or system reset.
The WKINTEN bit is used in the Multi-input Wakeup/Interrupt
block. See Section 8 for details.
Software can now read the difference between transitions
directly without using any processor resources. However, like
Figure 19. Timer 0 Control Register Definition (T0CNTRL)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
WKINTEN
x
x
x
x
x
T0PND
T0INTEN
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(See Table 11 and Table 12)
- LD T1CNTRL, #64H
; T1C1 is the edge select bit
The Watchdog timer is used to reset the device and safely
recover in the rare event of a processor “runaway condition.”
The 12-bit Timer 0 is used as a pre-scalar for Watchdog timer.
The Watchdog timer must be serviced before every 61,440
cycles but no sooner than 4096 cycles since the last Watchdog
reset. The Watchdog is serviced through software by writing the
value 0x1B to the Watchdog Service (WDSVR) register (see
Figure 20). The part resets automatically if the Watchdog is serviced too frequent, or not frequent enough.
can only be set while the device is in programming mode. Once
set, the Watchdog will always be powered-up enabled. Software
cannot disable the Watchdog. The Watchdog timer can only be
disabled in programming mode by resetting the WDEN bit as
long as the memory write protect (WDIS) feature is not enabled.
WARNING
Ensure that the Watchdog timer has been serviced before
entering IDLE mode because it remains operational during this
time.
The Watchdog timer must be enabled through the Watchdog
enable bit (WDEN) in the initialization register. The WDEN bit
Figure 20. Watchdog Service Register (WDSVR)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
1
1
0
1
1
7. Hardware Bit-Coder
The Hardware Bit-Coder is a dedicated hardware bit-encoding
peripheral block, Hardware Bit-Coder (HBC), for IR/RF data
transmission (see Figure 21.) The HBC is completely software
programmable and can be configured to emulate various bitencoding formats. The software developer has the freedom to
encode each bit of data into a desired pattern and output the
encoded data at the desired frequency through either the G2 or
G5 output (TX) ports.
pattern bits to be transmitted from each register. Upon a reset,
BPSEL is initially 0 disabling the HBC from transmitting pattern
bits from either register.
The Data (DAT0) register is used to store up to 8 bits of data to
be encoded and transmitted by the HBC. This data is shifted, bit
by bit, MSB to LSB into a 1-bit decision register. If the active bit
shifted into the decision register is 1, the pattern in the HPATTERN register is shifted out of the output port. Similarly, if the
active bit is 0 the pattern in the LPATTERN register is shifted
out.
The HBC contains six 8-bit memory-mapped configuration registers PSCALE, HPATTERN, LPATTERN, BPSEL, HBCNTRL,
and DAT0. The registers are used to select the transmission frequency, store the data bit-encoding patterns, configure the data
bit-pattern/frame lengths, and control the data transmission
flow.
The HBC control (HBCNTRL) register is used to configure and
control the data transmission. HBCNTRL is divided in 5 different
controlling signal FRAME[2:0], IOSEL, TXBUSY, START /
STOP, and OCFLAG (see Figure 23.)
To select the IR/RF transmission frequency, an 8-bit divide constant must be written into the IR/RF Pre-scalar (PSCALE) register. The IR/RF transmission frequency generator divides the
1MHz instruction clock down by 4 and the PSCALE register is
used to select the desired IR/RF frequency shift. Together, the
transmission frequency range can be configured between
976Hz (PSCALE = 0xFF) and 125kHz (PSCALE = 0x01). Upon
a reset, the PSCALE register is initialized to zero disabling the
IR/RF transmission frequency generator. However, once the
PSCALE register is programmed, the desired IR/RF frequency
is maintained as long as the device is powered.
FRAME[2:0] selects the number of bits of DAT0 to encode and
transmit. The HBC allows from 2 (0x1) to 8 (0x7) DAT0 bits to be
encoded and transmitted. Upon a reset, FRAME is initialized to
zero disabling the DAT0’s decision register transmitting no data.
The IOSEL signal selects the transmission to output (TX)
through either port G2 or G5. If IOSEL is 1, G5 is selected as
the output port otherwise G2 is selected.
The TXBUSY signal is read only and is used to inform software
that a transmission is in progress. TXBUSY goes high when the
encoded data begins to shift out of the output port and will
remains high during each consecutive DAT0 frame bit transmission (see Figure 25). The HBC will clear the TXBUSY signal
when the last DAT0 encoded bit of the frame is transmitted and
the STOP signal is 0.
Once the transmission frequency is selected, the data bitencoding patterns must be stored in the appropriate registers.
The HBC contains two 8-bit bit-encoding pattern registers,
High-pattern (HPATTERN) and Low-pattern (LPATTERN). The
encoding pattern stored in the HPATTERN register is transmitted when the data bit value to be encoded is a 1. Similarly, the
pattern stored in the LPATTERN register is transmitted when the
data bit value to be encoded is a 0. The HBC transmits each
encoded pattern MSB first.
The START / STOP signal controls the encoding and transmission process for each data frame. When software sets the
START / STOP bit the DAT0 frame transmission process begins.
The START signal will remain high until the beginning of the last
encoded DAT0 frame bit transmission. The HBC then clears the
START / STOP bit allowing software to elect to either continue
with a new DAT0 frame transmission or stop the transmission all
together (see Figure 25). If TXBUSY is 0 when the START signal is enabled, a synchronization period occurs before any data
is transmitted lasting the amount of time to transmit a 0 encoded
bit (see Figure 24).
The number of bits transmitted from the HPATTERN and LPATTERN registers is software programmable through the Bit
Period Configuration (BPSEL) register (see Figure 22). During
the transmission of HPATTERN, the number of bits transmitted
is configured by BPH[2:0] (BPSEL[2:0]) while BPL[2:0]
(BPSEL[5:3]) configures the number of transmitted bits for the
LPATTERN. The HBC allows from 2 (0x1) to 8 (0x7) encoding
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6. Watchdog
PSCALE, #03H
BPSEL, #012H
HPATTERN, #0C0H
LPATTERN, #090H
DAT0, #052H
; (1MHz ?? 4) ?? 4 = 62.5KHz
; BPH = 2, BPL = 2 (3 bits each)
; HPATTERN = 0xC0
; LPATTERN = 0x90
; DAT0 = 0x52
Once the basic registers are initialized, the HBC can be started.
(At the same time, software must set the number of data bits per
data frame and select the desired output port.)
LD
HBCNTRL, #27H
; START / STOP = 1,
FRAME = 7, IOSEL = 0
After the HBC has started, software must then poll the OCFLAG
for a high pulse and restore the DAT0 register and the START
signal to continue with the next data transmission.
LOOP_HI:
IFBIT OCFLAG, HBCNTRL
JP
NXT_FRAME
JP
LOOP_HI
Figure 24 and Figure 25 shows how the HBC performs its data
encoding. In the example, two frames are encoded and transmitted consecutively with the following bit encoding format specification:
; Wait for OCFLAG = 1
NXT_FRAME:
LD
DAT0, #092H
SBIT START, HBCNTRL
1. Transmission frequency = 62.5KHz
2. Data to be encoded = 0x52, 0x92 (all 8-bits)
; DAT0 = 0x92
; START / STOP = 1
If software is to proceed with another data transmission, the
OCFLAG must be zero before polling for the next OCFLAG high
pulse. However, since the specification in the example requires
no other data transmission software can proceed as desired.
3. Each bit should be encoded as a 3-bit binary value,
‘1’ = 110b and ‘0’ = 100b
4. Transmission output port : G2
LOOP_LO:
To perform the data transmission, software must first initialize
the PSCALE, BPSEL, HPATTERN, LPATTERN, and DAT0
registers with the appropriate values.
IFBIT OCFLAG, HBCNTRL
JP
LOOP_LO
Etc.
; Wait for OCFLAG = 0
; Program proceeds
as desired
Figure 21. Hardware Bit-coder (HBC) Block Diagram
IR/RF
CLOCK
RFCLK
HPATTERN
StopShift
b7
A
Y
G2
B
CPU
CLOCK
Fixed
Clock Divider
by 4
PSCALE
RFCLK
G5
b7
LPATTERN
StopShift
8
IOSEL
HBCNTRL[6]
[PSCALE]
ShiftCLK
Down
Counter
DAT0
NoShift
b7
OCFLAG
Sync
LOGIC
3
3
FRAME[2:0]
[HBCNTRL]
Y
A
3
BPH[2:0]
[BPSEL]
B
START/STOP
HBCNTRL[5]
TXBUSY
HBCNTRL[4]
3
BPL[2:0]
[BPSEL]
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OCFLAG
HBCNTRL[7]
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
LD
LD
LD
LD
LD
The OCFLAG signal is read only and goes high when the last
encoded bit of the DAT0 frame is transmitting. The OCFLAG signal is used to inform software that the DAT0 frame transmission
operation is completing (see Figure 25). If multiple DAT0 frames
are to be transmitted consecutively, software should poll the
OCFLAG signal for a 1. Once OCFLAG is 1, DAT0 must be
reload and the START / STOP bit must be restored to 1 in order
to begin the new frame transmission without interruptions (the
synchronization period). Since OCFLAG remains high during
the entire last encoded DAT0 frame bit transmission, software
should wait for the HBC to clear the OCFLAG signal before polling for the new OCFLAG high pulse. If new data is not reloaded
into DAT0 and the START signal (STOP is active) is not set
before the OCFLAG is 0, the transmission process will end
(TXBUSY is cleared) and a new process will begin starting with
the synchronization period.
Bit 7
Bit 6
0
0
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
BPL[2:0]
Bit 0
BPH[2:0]
Figure 23. HBC Control (HBCNTRL) Register
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
OCFLAG
IOSEL
START / STOP
TXBUSY
0
Bit 2
Bit 1
Bit 0
FRAME[2:0]
Figure 24. HBC signals for one byte message in PWM format
Condition:
BPSEL = 0x12 [ "1", " 0 " = 3 * IR/RF Clocks]
DAT0 = 0x52
No. bit to encode = 8 (HBCNTRL = XXXX0111b)
TXBUSY
START/STOP
ShiftCLK
OCFLAG
Bit 7
DAT0
"0"
"0"
"1"
"0"
"1"
"0"
"0"
"1"
"0"
G2/G5
Output
IR/RF
CLOCK
Figure 25. Sending series of encoded messages
Conditions:
BPSEL = 0x12 [ "1", " 0 " = 3 * IR/RF Clocks]
DAT0 = 0x52 , 0x92
No. bit to encode = 8 (HBCNTRL = XXXX0111b)
Software must set the START bit while OCFLAG is set in
order to send another message without introducing a delay.
TXBUSY
STOP bit clear,
transmission ends.
START/STOP
ShiftCLK
OCFLAG
Bit 7
DAT0
"0"
"0"
"1" "0"
"1" "0"
"0"
"1" "0"
"1"
"0" "0"
"1"
"0"
"0"
"1"
"0"
G2/G5
Output
IR/RF
CLOCK
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Figure 22. Bit Period Configuration (BPSEL) Register
6. Set the WKEN bits associated with the pins to be used, thus
enabling those pins for the Wakeup/Interrupt function.
- LD WKEN, #10H
; Enabling G4
The Multi-Input Wakeup (MIW)/Interrupt contains three
memory-mapped registers associated with this circuit: WKEDG
(Wakeup Edge), WKEN (Wakeup Enable), and WKPND
(Wakeup Pending). Each register has 8-bits with each bit
corresponding to an input pins as shown in Figure 27. All three
registers are initialized to zero upon reset.
Once the Multi-Input Wakeup/Interrupt function has been configured, a transition sensed on any of the I/O pins will set the
corresponding bit in the WKPND register. The WKPND bits,
where the corresponding enable (WKEN) bits are set, will bring
the device out of the HALT mode and can also trigger an interrupt if interrupts are enabled. The interrupt service routine can
read the WKPND register to determine which pin sensed the
interrupt.
The WKEDG register establishes the edge sensitivity for each
of the wake-up input pin: either positive going-edge (0) or
negative-going edge (1).
The WKEN register enables (1) or disables (0) each of the port
pins for the Wakeup/Interrupt function. The wakeup I/Os used
for the Wakeup/Interrupt function must also be configured as an
input pin in its associated port configuration register. However,
an interrupt of the core will not occur unless interrupts are
enabled for the block via bit 7 of the T0CNTRL register (see Figure 19) and the G (global interrupt enable) bit of the SR is set.
The interrupt service routine or other software should clear the
pending bit. The device will not enter HALT mode as long as a
WKPND pending bit is pending and enabled. The user has the
responsibility of clearing the pending flags before attempting to
enter the HALT mode.
Upon reset, the WKEDG register is configured to select positive-going edge sensitivity for all wakeup inputs. If the user
wishes to change the edge sensitivity of a port pin, use the following procedure to avoid false triggering of a Wakeup/Interrupt
condition.
The WKPND register contains the pending flags corresponding
to each of the port pins (1 for wakeup/interrupt pending, 0 for
wakeup/interrupt not pending). If an I/O is not selected to
become a wakeup input, the pending flag will not be generated.
1. Clear the WKEN bit associated with the pin to disable that
pin.
To use the Multi-Input Wakeup/Interrupt circuit, perform the
steps listed below making sure the MIW edge is selected before
enabling the I/O to be used as a wakeup input thus preventing
false pending flag generation. This same procedure should be
used following any type of reset because the wakeup inputs are
left floating after resets resulting in unknown data on the port
inputs.
2. Clear the WKPND bit associated with the pin.
3. Write the WKEDG register to select the new type of edge
sensitivity for the pin.
4. Set the WKEN bit associated with the pin to re-enable it.
PORTG provides the user with three fully selectable, edge sensitive interrupts that are all vectored into the same service subroutine. The interrupt from PORTG shares logic with the wakeup
circuitry. The WKEN register allows interrupts from PORTG to
be individually enabled or disabled. The WKEDG register specifies the trigger condition to be either a positive or a negative
edge. The WKPND register latches in the pending trigger conditions.
1. Clear the WKEN register.
- CLR WKEN
2. Clear the WKPND register to cancel any pending bits.
- CLR WKPND
3. If necessary, write to the port configuration register to select
the desired port pins to be configured as inputs.
- RBIT 4, PORTGC
; G4
Since PORTG is also used for exiting the device from the HALT
mode, the user can elect to exit the HALT mode either with or
without the interrupt enabled. If the user elects to disable the
interrupt, then the device restarts execution from the point at
which it was stopped (first instruction cycle of the instruction following HALT mode entrance instruction). In the other case, the
device finishes the instruction that was being executed when
the part was stopped and then branches to the interrupt service
routine. The device then reverts to normal operation.
4. If necessary, write to the port data register to select the
desired port pins input state.
- SBIT 4, PORTGD
; Pull-up
5. Write the WKEDG register to select the desired type of edge
sensitivity for each of the pins used.
- LD
WKEDG, #0FFH
; All negative-going edges
Figure 26. Multi-input Wakeup (MIW) Register bit assignments
WKEDG, WKEN, WKPND
Bit 7
9
G7
Bit 6
9
G6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
G5
G4
G3
G2
G1
G0
9. Available only on the 14-pin package option
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8. Multi-Input Wakeup/Interrupt Block
Data Bus
7
0
WKEN[7:0]
0
G0
WKOUT
EDGEI
7
G7
WKINTEN 10
WKPND[0:7]
WKEDG[0:7]
10.
WKINTEN: Bit 7 of T0CNTRL
9. I/O Port
9.1 I/O registers
The eight I/O pins (six on 8-pin package option) are bidirectional (see Figure 28). The bi-directional I/O pins can be
individually configured by software to operate as highimpedance inputs, as inputs with weak pull-up, or as push-pull
outputs. The operating state is determined by the contents of
the corresponding bits in the data and configuration registers.
Each bi-directional I/O pin can be used for general purpose I/O,
or in some cases, for a specific alternate function determined by
the on-chip hardware.
The I/O pins (G0-G7) have three memory-mapped port registers associated with the I/O circuitry: a port configuration register (PORTGC), a port data register (PORTGD), and a port input
register (PORTGP). PORTGC is used to configure the pins as
inputs or outputs. A pin may be configured as an input by writing
a 0 or as an output by writing a 1 to its corresponding PORTGC
bit. If a pin is configured as an output, its PORTGD bit represents the state of the pin (1 = logic high, 0 = logic low). If the pin
is configured as an input, its PORTGD bit selects whether the
pin is a weak pull-up or a high-impedance input. Table 13 provides details of the port configuration options. The port configuration and data registers can both be read from or written to.
Reading PORTGP returns the value of the port pins regardless
of how the pins are configured. Since this device supports MIW,
PORTG inputs have Schmitt triggers.
Figure 28. PORTGD Logic Diagram
GXPULLEN
GXBUFEN
GX
GXOUT
GXIN
Figure 29. I/O Register bit assignments
PORTGC, PORTGD, PORTGD
Bit 7
Bit 6
11G7
11G6
Bit 5
G5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
G4
12G3
G2
G1
G0
11. Available only on the 14-pin package option
12. G3 after reset is an input with weak pull-up
Table 13. I/O configuration options
Configuration Bit
Data Bit
Port Pin Configuration
0
0
High-impedence input (TRI-STATE input)
0
1
Input with pull-up (weak one input)
1
0
Push-pull zero output
1
1
Push-pull one output
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Figure 27. Multi-input Wakeup (MIW) Block Diagram
SHIFT_OUT pin. It is recommended that the external programmer samples this signal t ACCESS (500 ns) after the rising edge
of the CLOCK signal. The serial response word, sent immediately after entering programming mode, contains indeterminate
data.
The ACEx microcontroller supports in-circuit programming of
the internal data EEPROM, code EEPROM, and the initialization registers.
In order to enter into program mode a 10-bit opcode (0x34B)
must be shifted into the ACE1502 while the device is executing
the internal power on reset (TRESET). The shifting protocol follows the same timing rules as the programming protocol defined
in Figure 30.
After 32 bits have been shifted into the device, the external programmer must set the LOAD signal to 0V, and then apply two
clock pulses as shown in Figure 30 to complete program cycle.
The opcode is shifted into the ACE1502 serially, MSB first, with
the data being valid by the rising edge of the clock. Once the
pattern is shifted into the device, the current 10-bit pattern is
matched to protocol entrance opcode of 0x34B. If the 10-bit
pattern is a match, the device will enable the internal program
mode flag so that the device will enter into program mode once
reset has completed (see Figure 30.)
The SHIFT_OUT pin acts as the handshaking signal between
the device and programming hardware once the LOAD signal is
brought low. The device sets SHIFT_OUT low by the time the
programmer has sent the second rising edge during the LOAD
= 0V phase (if the timing specifications in Figure 30 are
obeyed).
The device will set the R bit of the Status register when the write
operation has completed. The external programmer must wait
for the SHIFT_OUT pin to go high before bringing the LOAD signal to Vcc to initiate a normal command cycle.
The opcode must be shifted in after Vcc settles to the nominal
level and should end before the power on reset sequence
(Treset) completes; otherwise, the device will start normal
execution of the program code. If the external reset is applied by
bringing the reset pin low, once the reset pin is release the
opcode may now be shifted in and again should end before the
reset sequence completes.
10.3.2 Read Sequence
When reading the device after a write, the external programmer
must set the LOAD signal to Vcc before it sends the new command word. Next, the 32-bit serial command word (for during a
READ) should be shifted into the device using the SHIFT_IN
and the CLOCK signals while the data from the previous command is serially shifted out on the SHIFT_OUT pin. After the
Read command has been shifted into the device, the external
programmer must, once again, set the LOAD signal to 0V and
apply two clock pulses as shown in Figure 30 to complete
READ cycle. Data from the selected memory location, will be
latched into the lower 8 bits of the command word shortly after
the second rising edge of the CLOCK signal.
10.3 Programming Protocol
After placing the device in program, the programming protocol
and commands may be issued.
An externally controlled four-wire interface consisting of a LOAD
control pin (G3), a serial data SHIFT-IN input pin (G4), a serial
data SHIFT-OUT output pin (G2), and a CLOCK pin (G1) is
used to access the on-chip memory locations. Communication
between the ACEx microcontroller and the external programmer
is made through a 32-bit command and response word
described in Table 14. Be sure to either float or tie G5 to Vcc for
proper programming functionality.
Writing a series of bytes to the device is achieved by sending a
series of Write command words while observing the devices
handshaking requirements.
The serial data timing for the four-wire interface is shown in Figure 31 and the programming protocol is shown in Figure 30.
Reading a series of bytes from the device is achieved by sending a series of Read command words with the desired
addresses in sequence and reading the following response
words to verify the correct address and data contents.
10.3.1 Write Sequence
The external programmer brings the ACEx microcontroller into
programming then needs to set the LOAD pin to Vcc before
shifting in the 32-bit serial command word using the SHIFT_IN
and CLOCK signals. By definition, bit 31 of the command word
is shifted in first. At the same time, the ACEx microcontroller
shifts out the 32-bit serial response to the last command on the
The addresses of the data EEPROM and code EEPROM
locations are the same as those used in normal operation.
Powering down the device will cause the part to exit programming mode.
Table 14 32-Bit Command and Response Word
Bit Number
Input Command Word
Output Response Word
bits 31-30
Must be set to 0
bit 29
Set to 1 to read/write data EEPROM, or the initialization X
registers, otherwise 0
X
bit 28
Set to 1 to read/write code EEPROM, otherwise 0
bits 27-25
Must be set to 0
X
bit 24
Set to 1 to read, 0 to write
X
bits 23-19
Must be set to 0
X
bits 18 -8
Address of the byte to be read or written
Same as Input command word
bits 7-0
Data to be programmed or zero if data is to be read
Programmed data or data read at specified address
23
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
10. In-circuit Programming Specification
A
VCC
Treset
RESET
tready
tload1 tload2
tload3
tload4
A
LOAD (G3)
32 clock pulses
CLOCK (G1)
SHIFT_IN (G4)
1
1
0
1
0
0
1
0
1
1
bit 31
bit 30
bit 0
bit 31
10-bit Opcode = 0x34B
READY
BUSY low by
2nd clock pulse
SHIFT_OUT (G2)
(in write mode)
BUSY
SHIFT_OUT (G2)
(in read mode)
A: start of programming cycle
13. During in-circuit programming, G5 must be either not connected or driven high.
Figure 31. Serial Data Timing
tHI
tLO
CLOCK (G1)
tDIS
tDIH
Valid
SHIFT_IN (G4)
tDOS
tDOH
Valid
SHIFT_OUT (G2)
tACCESS
11. Brown-out/Low Battery Detect Circuit
The Brown-out Reset (BOR) and Low Battery Detect (LBD)
circuits on the ACEx microcontroller have been designed to
offer two types of voltage reference comparators. The sections
below will describe the functionality of both circuits.
Figure 32. BOR/LBD Block Diagram
_
+1.8V
Vref
BOR
to RESET logic
+
Vcc
0
G4
1
S
_
LBD
Adjust Reference Voltage
7
BL[4]
6
BL[3]
5
BL[2]
4
BL[1]
+
3
BL[0]
2
VSEL
24
ACE1502 Product Family Rev. 1.7
1
X
0
LBD
LBD
Control
Register
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Figure 30. Programming Protocol13
Vcc does not fall below ~1.5V. The Power-on Reset circuit works
best when Vcc starts from zero and rises sharply. In applications where Vcc is not constant, the BOR will give added device
stability.
The Brown-out Reset (BOR) function is used to hold the device
in reset when Vcc drops below a fixed threshold (1.83V.) While
in reset, the device is held in its initial condition until Vcc rises
above the threshold value. Shortly after Vcc rises above the
threshold value, an internal reset sequence is started. After the
reset sequence, the core fetches the first instruction and starts
normal operation.
The BOR circuit must be enabled through the BOR enable bit
(BOREN) in the initialization register. The BOREN bit can only
be set while the device is in programming mode. Once set, the
BOR will always be powered-up enabled. Software cannot disable the BOR. The BOR can only be disabled in programming
mode by resetting the BOREN bit as long as the global write
protect (WDIS) feature is not enabled.
The BOR should be used in situations when Vcc rises and falls
slowly and in situations when Vcc does not fall to zero before
rising back to operating range. The Brown-out Reset can be
thought of as a supplement function to the Power-on Reset if
Figure 33. BOR and POR Circuit Relationship Diagram
Vcc (Pin 8)
BOR
output
VCC
1.75
VCC
0
VCC
0
Time
BOR Output
POR
output
External
Reset
Pin
(14-Pin Only)
VCC
5.0V
(Pin 7)
Reset
circuit
output
A
1.8V
0
VCC
POR
output
0
POR Output
Pulse
11.2 Low Battery Detect
Global Reset
to Logic
B
The Reset circuit will trigger
when inputs A or B transition
from High to Low. At that time
the Global Reset signal will go
high which will reset all
controller logic. The Global
Reset will go high and stay high
for around 1us.
resetting the LBDEN bit as long as the global write protect
(WDIS) feature is not enabled.
The Low Battery Detect (LBD) circuit allows software to monitor
the Vcc level at the lower voltage ranges. LBD has a 32-level
software programmable voltage reference threshold that can be
changed on the fly. Once Vcc falls below the selected threshold,
the LBD flag in the LBD control register is set. The LBD flag will
hold its value until Vcc rises above the threshold. (See Table 15)
The LBD circuit is disabled during HALT/IDLE mode. After exiting HALT/IDLE, software must wait at lease 10 µs before reading the LBD bit to ensure that the internal circuit has stabilized.
The LBD bit is read only. If LBD is 0, it indicates that the Vcc
level is higher than the selected threshold. If LBD is 1, it indicates that the Vcc level is below the selected threshold. The
threshold level can be adjusted up to eight levels using the three
trim bits (BL[4:0]) of the LBD control register. The LBD flag does
not cause any hardware actions or an interruption of the processor. It is for software monitoring only.
The VSEL bit of the LBD control register can be used to select
an external voltage source rather than Vcc. If VSEL is 1, the
voltage source for the LBD comparator will be an input voltage
provided through G4. If VSEL is 0, the voltage source will be
Vcc.
The LBD circuit must be enabled through the LBD enable bit
(LBDEN) in the initialization register. The LBDEN bit can only be
set while the device is in programming mode. Once set, the LBD
will always be powered-up enabled. Software cannot disable the
LBD. The LBD can only be disabled in programming mode by
25
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
11.1 Brown-out Reset
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
BL[4:0]
Bit 2
Bit 1
Bit 0
VSEL
X
LBD
Level
BL[4]
BL[3]
BL[2]
BL[1]
BL[0]
Voltage Reference Range (Typical)
1
0
0
0
0
0
1.81V
2
0
0
0
0
1
1.87V
3
0
0
0
1
0
1.93V
4
0
0
0
1
1
1.99V
5
0
0
1
0
0
2.05V
6
0
0
1
0
1
2.11V
7
0
0
1
1
0
2.17V
8
0
0
1
1
1
2.23V
9
0
1
0
0
0
2.29V
10
0
1
0
0
1
2.36V
11
0
1
0
1
0
2.42V
12
0
1
0
1
1
2.48V
13
0
1
1
0
0
2.54V
14
0
1
1
0
1
2.60V
15
0
1
1
1
0
2.66V
16
0
1
1
1
1
2.72V
17
1
0
0
0
0
2.77V
18
1
0
0
0
1
2.84V
19
1
0
0
1
0
2.91V
20
1
0
0
1
1
2.97V
21
1
0
1
0
0
3.03V
22
1
0
1
0
1
3.09V
23
1
0
1
1
0
3.16V
24
1
0
1
1
1
3.22V
25
1
1
0
0
0
3.28V
26
1
1
0
0
1
3.34V
27
1
1
0
1
0
3.41V
28
1
1
0
1
1
3.47V
29
1
1
1
0
0
3.54V
30
1
1
1
0
1
3.60V
31
1
1
1
1
0
3.67V
32
1
1
1
1
1
3.73V
26
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Table 15. LBD Control Register Definition
When a RESET sequence is initiated, all I/O registers will be
reset setting all I/Os to high-impedence inputs. The system
clock is restarted after the required clock start-up delay. A reset
is generated by any one of the following four conditions:
• Power-on Reset (as described in Section 13)
• Brown-out Reset (as described in Section 11.1)
• Watchdog Reset (as described in Section 6)
• External Reset 18 (as described in Section 13)
18. Available only on the 14-pin package option
13. Power-On Reset
The Power-On Reset (POR) circuit is guaranteed to work if the
rate of rise of Vcc is no slower than 10ms/1volt. The POR circuit
was designed to respond to fast low to high transitions between
0V and Vcc. The circuit will not work if Vcc does not drop to 0V
before the next power-up sequence. In applications where 1)
the Vcc rise is slower than 10ms/1 volt or 2) Vcc does not drop
to 0V before the next power-up sequence the external reset
option should be used.
The external reset provides a way to properly reset the ACEx
microcontroller if POR cannot be used in the application. The
external reset pin contains an internal pull-up resistor. Therefore, to reset the device the reset pin should be held low for at
least 2ms so that the internal clock has enough time to stabilize.
14. CLOCK
Figure 34. Crystal
The ACEx microcontroller has an on-board oscillator trimmed to
a frequency of 2MHz who is divided down by two yielding a
1MHz frequency. (See AC Electrical Characteristics) Upon
power-up, the on-chip oscillator runs continuously unless entering HALT mode or using an external clock source.
CKI
If required, an external oscillator circuit may be used depending
on the states of the CMODE bits of the initialization register.
(See Table 16) When the device is driven using an external
clock, the clock input to the device (G1/CKI) can range between
DC to 4MHz. For external crystal configuration, the output clock
(CKO) is on the G0 pin. (See Figure 34.) If the device is configured for an external square clock, it will not be divided.
CKO
R2
R1
Table 16. CMODEx Bit Definition
CMODE [1] CMODE [0]
C2
Clock Type
0
0
Internal 1 MHz clock
0
1
External square clock
1
0
External crystal/resonator
1
1
Reserved
C1
15. HALT Mode
The HALT mode is a power saving feature that almost completely shuts down the device for current conservation. The
device is placed into HALT mode by setting the HALT enable bit
(EHALT) of the HALT register through software using only the
“LD M, #” instruction. EHALT is a write only bit and is automatically cleared upon exiting HALT. When entering HALT, the internal oscillator and all the on-chip systems including the LBD and
the BOR circuits are shut down.
The device can exit HALT mode only by the MIW circuit. Therefore, prior to entering HALT mode, software must configure the
MIW circuit accordingly. (See Section 8) After a wakeup from
HALT, a 1ms start-up delay is initiated to allow the internal oscillator to stabilize before normal execution resumes. Immediately
after exiting HALT, software must clear the Power Mode Clear
(PMC) register by only using the “LD M, #” instruction. (See Figure 36)
Figure 35. HALT Register Definition
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Undefined
undefined
undefined
undefined
undefined
undefined
EIDLE
EHALT
27
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
12. RESET block
ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Figure 36. Recommended HALT Flow
Normal Mode
LD
Multi-Input
Wakeup
HALT, #01H
HALT Mode
LD
PMC, #00H
Resume Normal
Mode
16. IDLE Mode
In addition to the HALT mode power saving feature, the device
also supports an IDLE mode operation. The device is placed
into IDLE mode by setting the IDLE enable bit (EIDLE) of the
HALT register through software using only the “LD M, #” instruction. EIDLE is a write only bit and is automatically cleared upon
exiting IDLE. The IDLE mode operation is similar to HALT
except the internal oscillator, the Watchdog, and the Timer 0
remain active while the other on-chip systems including the LBD
and the BOR circuits are shut down.
The device automatically wakes from IDLE mode by the Timer 0
overflow every 8192 cycles (see Section 5). Before entering
IDLE mode, software must clear the WKEN register to disable
the MIW block. Once a wake from IDLE mode is triggered, the
core will begin normal operation by the next clock cycle. Immediately after exiting IDLE mode, software must clear the Power
Mode Clear (PMC) register by using only the “LD M, #” instruction. (See Figure 37.)
Figure 37. Recommended IDLE Flow
Normal Mode
LD
HALT, #02H
Timer0
Underflow
IDLE Mode
Multi-Input
Wakeup
LD
PMC, #00H
Resume Normal
Mode
28
ACE1502 Product Family Rev. 1.7
www.fairchildsemi.com
Core Type
Part Number
Max. #
Program
Operating
I/Os Memory Size Voltage Range
0 1 2 5
8
ACE1502EM8
X
ACE1502EM8X
X
ACE1502EM
1K
Package
-40 to -40 to
+85°C +125°C
8-pin
SOIC
14-pin
SOIC
8-pin
DIP
Tape
14-pin 8-pin 14-pin
&
DIP TSSOP TSSOP Reel
2K
1.8 – 3.6V
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ACE1502EMX
X
X
X
X
X
X
ACE1502EMT8
X
X
X
X
X
X
ACE1502EMT8X
X
X
X
X
X
X
ACE1502EMT
X
X
X
X
X
X
ACE1502EMTX
X
X
X
X
X
X
ACE1502EN
X
X
X
X
X
ACE1502EN14
X
X
X
X
X
ACE1502VM8
X
X
X
X
X
X
ACE1502VM8X
X
X
X
X
X
X
ACE1502VM
X
X
X
X
X
X
ACE1502VMX
X
X
X
X
X
X
ACE1502VMT8
X
X
X
X
X
X
ACE1502VMT8X
X
X
X
X
X
X
ACE1502VMT
X
X
X
X
X
ACE1502VMTX
X
X
X
X
X
ACE1502VN
X
X
X
X
X
ACE1502VN14
X
X
X
X
X
29
ACE1502 Product Family Rev. 1.7
X
X
X
X
X
X
X
X
X
X
X
X
X
X
www.fairchildsemi.com
ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Ordering Information
ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Physical Dimensions inches (millimeters) unless otherwise noted)
0.189 - 0.197
(4.800 - 5.004)
8 7 6 5
0.228 - 0.244
(5.791 - 6.198)
1 2 3 4
Lead #1
IDENT
0.010 - 0.020
x 45¡
(0.254 - 0.508)
0.0075 - 0.0098
(0.190 - 0.249)
Typ. All Leads
0.150 - 0.157
(3.810 - 3.988)
0.053 - 0.069
(1.346 - 1.753)
8¡ Max, Typ.
All leads
0.004 - 0.010
(0.102 - 0.254)
Seating
Plane
0.004
(0.102)
All lead tips
0.014
(0.356)
0.016 - 0.050
(0.406 - 1.270)
Typ. All Leads
0.014 - 0.020 Typ.
(0.356 - 0.508)
0.050
(1.270)
Typ
Molded Small Out-Line Package (M8)
Order Number ACE1502EM8/ACE1502VM8
Package Number M08A
0.373 - 0.400
(9.474 - 10.16)
0.090
(2.286)
8
0.092
DIA
(2.337)
7
6
0.032 ± 0.005
0.250 - 0.005
(6.35 ± 0.127)
+
Pin #1 IDENT
8
Pin #1
IDENT
1
Option 1
1
0.280 MIN
(7.112)
0.300 - 0.320
(7.62 - 8.128)
7
(0.813 ± 0.127)
RAD
5
2
0.040 Typ.
(1.016)
0.030
MAX
(0.762)
20° ± 1°
3
4
Option 2
0.145 - 0.200
(3.683 - 5.080)
0.039
(0.991)
0.130 ± 0.005
(3.302 ± 0.127)
95° ± 5°
0.009 - 0.015
(0.229 - 0.381)
+0.040
0.325 -0.015
+1.016
8.255 -0.381
0.125
(3.175)
DIA
NOM
0.125 - 0.140
(3.175 - 3.556)
0.065
(1.651)
90° ± 4°
Typ
0.018 ± 0.003
(0.457 ± 0.076)
0.100 ± 0.010
(2.540 ± 0.254)
0.045 ± 0.015
(1.143 ± 0.381)
0.020
(0.508)
Min
0.060
(1.524)
0.050
(1.270)
8-Pin DIP (N)
Order Number ACE1502EN/ACE1502VN
Package Number N08A
30
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Physical Dimensions inches (millimeters) unless otherwise noted)
0.114 - 0.122
(2.90 - 3.10)
8
5
(4.16) Typ (7.72) Typ
0.169 - 0.177
(4.30 - 4.50)
0.246 - 0.256
(6.25 - 6.5)
(1.78) Typ
(0.42) Typ
0.123 - 0.128
(3.13 - 3.30)
(0.65) Typ
1
Land pattern recommendation
4
Pin #1 IDENT
0.0433
Max
(1.1)
0.0256 (0.65)
Typ.
0.0035 - 0.0079
See detail A
0.002 - 0.006
(0.05 - 0.15)
0.0075 - 0.0118
(0.19 - 0.30)
Gage
plane
0 -8
DETAIL A
Typ. Scale: 40X
0.020 - 0.028
(0.50 - 0.70)
0.0075 - 0.0098
(0.19 - 0.25)
Seating
plane
Notes: Unless otherwise specified
1. Reference JEDEC registration MO153. Variation AA. Dated 7/93
8-Pin TSSOP
Order Number ACE1502EMT8/ACE1502VMT8
Package Number MT08A
5.0 –0.1
-A-
14
8
(4.16) Typ (7.72) Typ
4.4 – 0.1
-B-
6.4
(1.78) Typ
(0.42) Typ
3.2
(0.65) Typ
1
7
0.2 C B A
All Lead Tips
Land pattern recommendation
Pin #1 IDENT
1.1 Max
TYP
0.1 C
All Lead Tips
See detail A
(0.9)
0.9 - 0.20 TYP
-C0.10 – 0.05 TYP
0.65 Typ.
0.19 - 0.30 TYP
0.13 M A B s C s
Gage
plane
0¡-8¡
0.25
Dimensions are in millimeters
0.6 –0.1
Seating
plane
DETAIL A
Typ. Scale: 40X
Notes: Unless otherwise specified
1. Reference JEDED registration MO153. Variation AB.
Ref. Note 6, dated 7/93
14-Pin TSSOP
Order Number ACE1502EMT/ACE1502VMT
Package Number MT14A
31
ACE1502 Product Family Rev. 1.7
www.fairchildsemi.com
0.335 - 0.344
(8.509 - 8.788)
14 13 12 11 10 9
8
0.228 - 0.244
(5.791 - 6.198)
0.010
Max.
(0.254)
1
2
3
4
Lead #1
IDENT
0.010 - 0.020
x 45
(0.254 - 0.508)
0.008 - 0.010
(0.203 - 0.254)
Typ. all leads
0.150 - 0.157
(3.810 - 3.988)
8 Max, Typ.
All leads
0.04
(0.102)
All lead tips
5
6
7
30 Typ.
0.053 - 0.069
(1.346 - 1.753)
0.004 - 0.010
(0.102 - 0.254)
Seating
Plane
0.014
(0.356)
0.016 - 0.050
(0.406 - 1.270)
Typ. All Leads
0.050
(1.270)
Typ
0.014 - 0.020 Typ.
(0.356 - 0.508)
0.008
Typ
(0.203)
Molded Small Out-Line Package (M)
Order Number ACE1502EM/ACE1502EM
Package Number M14A
14-Pin DIP (N14)
Order Number ACE1502EN14/ACE1502VN14
Package Number N14A
32
ACE1502 Product Family Rev. 1.7
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
Physical Dimensions inches (millimeters) unless otherwise noted)
Prototype Board Kits: Fairchild offers two solutions for the simplification of the breadboard operation so that ACEx Applications can be quickly tested.
General Information:
1) ACEDEMO can be used for general purpose applications
Fairchild Semiconductor offers different possibilities to evaluate
and emulate software written for ACEx.
2) ACETXRX is for transmitting / receiving (RF, IR, RS232,
RS485) applications.
Simulator: Is a Windows program able to load, assemble, and
debug ACEx programs. It is possible to place as many breakpoints as needed, trace the program execution in symbolic format, and program a device with the proper options. The ACEx
Simulator is available free-of-charge and can be downloaded
from Fairchild’s web site at www.fairchildsemi.com/products/
memory/ace
ACEDEMO has 8 switches, 8 LEDs, RS232 voltage translator,
buzzer, and a lamp with a small breadboard area.
Factory Programming:
Fairchild offers factory pre-programming and serialization (for
justified quantities) for a small additional cost. Please refer to
your local distributor for details regarding factory programming.
Ordering P/Ns
Emulator Kit and Programming adapters:
Please refer to your local distributor for details regarding development tools.
ACEx Emulator Kit: Fairchild also offers a low cost real-time incircuit emulator kit that includes:
Emulator board
Emulator software
Assembler and Manuals
Power supply
DIP14 target cable
PC cable
The ACEx emulator allows for debugging the program code in a
symbolic format. It is possible to place one breakpoint and
watch various data locations. It also has built-in programming
capability.
Life Support Policy
Fairchild's products are not authorized for use as critical components in life support devices or systems without the express written
approval of the President of Fairchild Semiconductor Corporation. As used herein:
1. Life support devices or systems are devices or systems which,
(a) are intended for surgical implant into the body, or (b) support
or sustain life, and whose failure to perform, when properly
used in accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a significant
injury to the user.
Fairchild Semiconductor
Americas
Customer Response Center
Tel. 1-888-522-5372
Fairchild Semiconductor
Europe
Fax: +44 (0) 1793-856858
Deutsch
Tel: +49 (0) 8141-6102-0
English
Tel: +44 (0) 1793-856856
Français
Tel: +33 (0) 1-6930-3696
Italiano
Tel: +39 (0) 2-249111-1
Fairchild Semiconductor
Hong Kong
8/F, Room 808, Empire Centre
68 Mody Road, Tsimshatsui East
Kowloon. Hong Kong
Tel; +852-2722-8338
Fax: +852-2722-8383
33
ACE1502 Product Family Rev. 1.7
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
Fairchild Semiconductor
Japan Ltd.
4F, Natsume Bldg.
2-18-6, Yushima, Bunkyo-ku
Tokyo, 113-0034 Japan
Tel: 81-3-3818-8840
Fax: 81-3-3818-8841
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ACE1502 Product Family Arithmetic Controller Engine (ACEx™) for Low Power Applications
ACEx Development Tools