ML63611 User’s Manual
Chapter 2 CPU and Memory Spaces
2 – 6
OPTION B (D): 1.5 V (3.0 V), With regulator
circuit for LCD bias
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
2.2.8 Register Stack Pointer (RSP) and Register Stack
The register stack pointer (RSP) is a pointer that indicates the register stack address for saving various registers.
RSP is a 4-bit up/down counter that is incremented during stack saves (execution of PUSH instructions) and is
decremented during stack restores (execution of POP instructions).
The register stack has 16 levels from address 0H to address 0FH. The contents of the register stack cannot be read
or written by the program.
Figure 2-4 shows the relation between RSP and the register stack.
Figure 2-4 Relation between RSP and Register Stack
The various registers shown in Figure 2-5 are saved onto and restored from the register stack by PUSH and POP
instructions.
Figure 2-5 Register Save/Restore by Execution of PUSH/POP Instructions
RSP is assigned to special function register (SFR) address 0F6H.
At system reset, RSP is initialized to “0” and points to address “0H” of the register stack.
2
1
0
RSP
Register stack pointer
Register stack
0FH
16 levels
0H
16 bits
3
L
H
A
Z
C
G
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Register stack
“PUSH HL” and “POP HL” instruction execution
Y
X
CBR
EBR
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Register stack
“PUSH XY” and “POP XY” instruction execution
rsp3
rsp2
rsp1
rsp0
RSP (0F6H)
bit 3
bit 2
bit 1
bit 0
(R/W)
Содержание ML63611
Страница 9: ...Chapter 1 Overview...
Страница 33: ...Chapter 2 CPU and Memory Spaces...
Страница 42: ...Chapter 3 CPU Control Functions...
Страница 49: ...Chapter 4 Interrupt INT...
Страница 62: ...Chapter 5 Clock Generator Circuit OSC...
Страница 71: ...Chapter 6 Time Base Counter TBC...
Страница 75: ...Chapter 7 Timers TIMER...
Страница 99: ...Chapter 8 100 Hz Timer Counter 100HzTC...
Страница 103: ...Chapter 9 Watchdog Timer WDT...
Страница 108: ...Chapter 10 Ports INPUT I O PORT...
Страница 140: ...Chapter 11 Melody Driver MELODY...
Страница 152: ...Chapter 12 Serial Port SIO...
Страница 179: ...Chapter 13 LCD Driver LCD...
Страница 200: ...Chapter 14 Battery Low Detect Circuit BLD...
Страница 204: ...Chapter 15 Power Supply Circuit POWER...
Страница 215: ...Chapter 16 A D Converter ADC...
Страница 238: ...Appendixes...
Страница 271: ...ML63611 User s Manual First Edition May 2001 Second Edition June 2001 2001 Oki Electric Industry Co Ltd PEUL63611 02...