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CMS80F731x Reference Manual
1.9
Program Counter (PC)
The program counter (PC) controls the order of instruction execution in the program memory FLASH, it can address the
entire flash range, after obtaining the instruction code, the program counter (PC) will automatically add one, pointing to the
address of the next instruction code. However, when performing operations such as jumps, conditional jumps, assigning values
to PCL, subroutine calls, initial resets, interrupts, interrupt returns, subprogram returns, etc., the PC loads the address associated
with the instruction instead of the address of the next instruction.
When a conditional jump instruction is encountered and the jump condition is met, the next instruction read during the
execution of the current instruction will be discarded and an empty instruction operation cycle will be inserted before the correct
instruction can be obtained. Instead, the next instruction is executed sequentially.
1.10 Timing Access Register (TA)
Timing access register TA
0x96
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
HE
TA7
TA6
TA5
TA4
TA3
TA2
TA1
TA0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset value
0
0
0
0
0
0
0
0
Bit7~Bit0
TA<7:0>:
Timing access control bits.
Some protected registers must be written to the TA before they can be performed
as follows.
MOV
HE, #0AAH
MOV
TA, #055H
No other instructions can be inserted in the middle, and this sequence needs to
be re-executed when modified again.
Protected registers:
WDCON
，
CLKDIV
，
SCKSEL
，
MLOCK.
