參數(shù)資料
型號: MC80C52XXX-25/883
廠商: TEMIC SEMICONDUCTORS
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CDIP40
文件頁數(shù): 6/83頁
文件大?。?/td> 8336K
代理商: MC80C52XXX-25/883
14
8021G–AVR–03/11
ATmega329P/3290P
6.5.1
The X-register, Y-register, and Z-register
The registers R26...R31 have some added functions to their general purpose usage. These reg-
isters are 16-bit address pointers for indirect addressing of the data space. The three indirect
address registers X, Y, and Z are defined as described in Figure 6-3.
Figure 6-3.
The X-, Y-, and Z-registers
In the different addressing modes these address registers have functions as fixed displacement,
automatic increment, and automatic decrement (see the instruction set reference for details).
6.6
Stack Pointer
The Stack is mainly used for storing temporary data, for storing local variables and for storing
return addresses after interrupts and subroutine calls. Note that the Stack is implemented as
growing from higher to lower memory locations. The Stack Pointer Register always points to the
top of the Stack. The Stack Pointer points to the data SRAM Stack area where the Subroutine
and Interrupt Stacks are located. A Stack PUSH command will decrease the Stack Pointer.
The Stack in the data SRAM must be defined by the program before any subroutine calls are
executed or interrupts are enabled. Initial Stack Pointer value equals the last address of the
internal SRAM and the Stack Pointer must be set to point above start of the SRAM, see Figure
See Table 6-1 for Stack Pointer details.
The AVR Stack Pointer is implemented as two 8-bit registers in the I/O space. The number of
bits actually used is implementation dependent. Note that the data space in some implementa-
tions of the AVR architecture is so small that only SPL is needed. In this case, the SPH Register
will not be present.
15
XH
XL
0
X-register
70
7
0
R27 (0x1B)
R26 (0x1A)
15
YH
YL
0
Y-register
70
7
0
R29 (0x1D)
R28 (0x1C)
15
ZH
ZL
0
Z-register
70
7
0
R31 (0x1F)
R30 (0x1E)
Table 6-1.
Stack Pointer instructions
Instruction
Stack pointer
Description
PUSH
Decremented by 1
Data is pushed onto the stack
CALL
ICALL
RCALL
Decremented by 2
Return address is pushed onto the stack with a subroutine call or
interrupt
POP
Incremented by 1
Data is popped from the stack
RET
RETI
Incremented by 2
Return address is popped from the stack with return from
subroutine or return from interrupt
相關(guān)PDF資料
PDF描述
MQ80C52EXXX-25:R 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CQFP44
MR80C32-12P883 8-BIT, 12 MHz, MICROCONTROLLER, CQCC44
MC80C32-36SHXXX 8-BIT, 36 MHz, MICROCONTROLLER, CDIP40
MQ80C32-20:RD 8-BIT, 20 MHz, MICROCONTROLLER, CQFP44
MQ80C52TXXX-16SHXXX:RD 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CQFP44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC80D21000G 制造商:COR 功能描述:RN
MC80F0104 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0104B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0104D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS
MC80F0204 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-BIT SINGLE-CHIP MICROCONTROLLERS