SyncMOS Technologies International, Inc.
SM5964A
8-Bit Micro-controller
With 64KB ISP Flash & TWSI & PWM & 1KB RAM embedded
CJNZ
CJNZ
CJNZ
A, #data,rel
3
3
3
2
2
2
Jump if A ≠ < #data >
Rn, #data,rel
@Ri, #data,rel
Jump if Rn ≠ < #data >
Jump if @Ri ≠ < #data >
Decrement and jump if Rn not zero
Decrement and jump if direct not zero
No Operation
DJNZ
DJNZ
NOP
Rn,rel
direct,rel
2
3
1
2
2
1
Memory organization
The central processing unit (CPU) manipulates operands in three memory spaces; there are 1024 bytes internal data
memory (consisting of 256 bytes standard RAM and 768 bytes AUX-RAM) and 64K bytes internal/external program
memory (see FIGURE 16)
64K
64K
Overlapped space
External
FLASH
memory
Internal
FLASH
memory
02FF
XRAM
(OME=0)
DIRECT
(SFR)
INDIRECT
ONLY
/EA=0
/EA=1
XRAM
(OME=1)
0080
0000
DIRECT AND
INDIRECT
0000
0000
External
DATA memory
Program memory
Internal DATA memory
Figure 16 Memory organization of SM5964A
Program memory
The program memory of SM5964A consists of 64K bytes FLASH memory on chip. If during RESET, the /EA pin was
held HIGH, the SM5964A does not execute out of the internal program memory. If the /EA pin was held LOW during
RESET the SM5964A fetch all instructions from the external program memory. The FLASH memory of SM5964A can be
programmed during the program is running by using ISP. Normally, a Writer is used for programming. The feature of
FLASH memory is shown as following:
z
z
z
READ:
byte-wise
WRITE: byte-wise within 30us (previously erased by a chip erase).
ERASE:
Full Erase (64K bytes) within 2 sec.
Erased bytes contain FFH
z
z
Endurance : 10K erase and write cycles each byte at TA=25℃
Retention : 10 years
Program Code Security
MOVC instruction executed from external program memory space will not be able to fetch internal codes from on chip
program memory after the chip is protected on the Writer.
Specifications subject to change without notice contact your sales representatives for the most recent information.
Ver 2.3 SM5964A 10/2006
19
SYNCMOS [ SYNCMOS TECHNOLOGIES,INC ]
