收藏本站
参数资料
型号： ST72C254G1B7
厂商： STMICROELECTRONICS
元件分类： 微控制器/微处理器
英文描述： 8-BIT, FLASH, 6 MHz, MICROCONTROLLER, PDIP32
封装： SHRINK, PLASTIC, DIP-32
文件页数： 43/136页
文件大小： 929K
代理商： ST72C254G1B7
ST72104G, ST72215G, ST72216G, ST72254G
14/136
6 CENTRAL PROCESSING UNIT (Cont’d)
Stack Pointer (SP)
Read/Write
Reset Value: 01 7Fh
The Stack Pointer is a 16-bit register which is al-
ways pointing to the next free location in the stack.
It is then decremented after data has been pushed
onto the stack and incremented before data is
popped from the stack (see Figure 7).
Since the stack is 128 bytes deep, the 9 most sig-
nificant bits are forced by hardware. Following an
MCU Reset, or after a Reset Stack Pointer instruc-
tion (RSP), the Stack Pointer contains its reset val-
ue (the SP6 to SP0 bits are set) which is the stack
higher address.
The least significant byte of the Stack Pointer
(called S) can be directly accessed by a LD in-
struction.
Note: When the lower limit is exceeded, the Stack
Pointer wraps around to the stack upper limit, with-
out indicating the stack overflow. The previously
stored information is then overwritten and there-
fore lost. The stack also wraps in case of an under-
flow.
The stack is used to save the return address dur-
ing a subroutine call and the CPU context during
an interrupt. The user may also directly manipulate
the stack by means of the PUSH and POP instruc-
tions. In the case of an interrupt, the PCL is stored
at the first location pointed to by the SP. Then the
other registers are stored in the next locations as
shown in Figure 7.
– When an interrupt is received, the SP is decre-
mented and the context is pushed on the stack.
– On return from interrupt, the SP is incremented
and the context is popped from the stack.
A subroutine call occupies two locations and an in-
terrupt five locations in the stack area.
Figure 7. Stack Manipulation Example
15
8
00
00000
1
70
0
SP6
SP5
SP4
SP3
SP2
SP1
SP0
PCH
PCL
SP
PCH
PCL
SP
PCL
PCH
X
A
CC
PCH
PCL
SP
PCL
PCH
X
A
CC
PCH
PCL
SP
PCL
PCH
X
A
CC
PCH
PCL
SP
Y
CALL
Subroutine
Interrupt
Event
PUSH Y
POP Y
IRET
RET
or RSP
@ 017Fh
@ 0100h
Stack Higher Address = 017Fh
Stack Lower Address = 0100h
相关PDF资料
PDF描述
ST72C334J2TC 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP44
ST72314N2TB/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP64
ST72C314N4TC 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PQFP64
ST72124J2TC/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP44
ST72334J4TB/XXX 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PQFP44
相关代理商/技术参数
参数描述
ST72C254G1M6 功能描述:8位微控制器 -MCU Flash 4K SPI/I2C RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72C254G2B1 制造商:STMicroelectronics 功能描述:8-BIT MICROCONTROLLER - Bulk
ST72C254G2B6 功能描述:8位微控制器 -MCU Flash 8K SPI/I2C RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
ST72C254G2B6 制造商:STMicroelectronics 功能描述:8BIT MCU FLASH 8K 72C254 DIP32
ST72C254G2M3 功能描述:8位微控制器 -MCU ST72104G ST72215G ST72254G 8B MCU RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*