tmp88cu74 TOSHIBA Semiconductor CORPORATION, tmp88cu74 Datasheet - Page 33

• Manufacturer Part Number: tmp88cu74
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

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(a) Saving/restoring by register bank changeover
Time
Main task
SP
Bank m
Bank m
At acceptance
of an interrupt
PSWH
PSWL
Acceptance
of interrupt
PCH
PCL
PCE
Interrupt return
4.
register during processing of single interrupt.
General-purpose registers save/restore using data transfer instructions
Example: Saving/restoring a register using data transfer instructions
PINTxx:
Figure 1.5.4 Saving/Restoring General-purpose Registers
SP
Data transfer instruction can be used to save only a specific general-purpose
Interrupt
service task
Bank m
Bank n
At execution of a
push instruction
PSWH
PSWL
PCH
PCE
LD
LD
RETI
PCL
Interrupt processing
W
A
Switch to bank n by LD,
RBS and n instruction
Switch to bank n
automatically
Restore to bank m
automatically by
[RETI]/[RETN]
(GSAVA), A
A, (GSAVA)
88CU74-33
SP
At execution of a
(b) Saving/restoring using push/pop or data transfer instructions
pop instruction
PSWH
PSWL
PCH
PCL
PCE
Main task
SP
;
;
;
Acceptance
of interrupt
Interrupt return
Save A register
Restore A register
Return
At execution of an
interrupt return
instruction
Interrupt
service task
Address (example)
0023AH
0023B
0023C
0023D
0023E
0023F
00240
00241
TMP88CU74
2007-10-19
2003-02-17
Saving
registers
Restoring
registers