参数资料
型号: PIC17C44
元件分类: 外设及接口
英文描述: Low Power 5V RS232 Dual Driver/Receiver with 0.1?μF Capacitors; Package: SO; No of Pins: 16; Temperature Range: -40?°C to 85?°C
中文描述: 电可擦除可编程逻辑器件
文件页数: 33/71页
文件大小: 1173K
代理商: PIC17C44
1996 Microchip Technology Inc.
DS30412C-page 39
PIC17C4X
6.3
Stack Operation
The PIC17C4X devices have a 16 x 16-bit wide hard-
ware stack (Figure 6-1). The stack is not part of either
the program or data memory space, and the stack
pointer is neither readable nor writable. The PC is
“PUSHed” onto the stack when a CALL instruction is
executed or an interrupt is acknowledged. The stack is
“POPed” in the event of a RETURN, RETLW, or a RETFIE
instruction execution. PCLATH is not affected by a
“PUSH” or a “POP” operation.
The stack operates as a circular buffer, with the stack
pointer initialized to '0' after all resets. There is a stack
available bit (STKAV) to allow software to ensure that
the stack has not overowed. The STKAV bit is set after
a device reset. When the stack pointer equals Fh,
STKAV is cleared. When the stack pointer rolls over
from Fh to 0h, the STKAV bit will be held clear until a
device reset.
After the device is “PUSHed” sixteen times (without a
“POP”), the seventeenth push overwrites the value
from the rst push. The eighteenth push overwrites the
second push (and so on).
Note 1: There is not a status bit for stack under-
ow. The STKAV bit can be used to detect
the underow which results in the stack
pointer being at the top of stack.
Note 2: There are no instruction mnemonics
called PUSH or POP. These are actions
that occur from the execution of the CALL,
RETURN
, RETLW, and RETFIE instruc-
tions, or the vectoring to an interrupt vec-
tor.
Note 3: After a reset, if a “POP” operation occurs
before a “PUSH” operation, the STKAV bit
will be cleared. This will appear as if the
stack is full (underow has occurred). If a
“PUSH” operation occurs next (before
another “POP”), the STKAV bit will be
locked clear. Only a device reset will
cause this bit to set.
6.4
Indirect Addressing
Indirect addressing is a mode of addressing data
memory where the data memory address in the
instruction is not xed. That is, the register that is to be
read or written can be modied by the program. This
can be useful for data tables in the data memory.
Figure 6-10 shows the operation of indirect address-
ing. This shows the moving of the value to the data
memory address specied by the value of the FSR
register.
Example 6-1 shows the use of indirect addressing to
clear RAM in a minimum number of instructions. A
similar concept could be used to move a dened num-
ber of bytes (block) of data to the USART transmit reg-
ister (TXREG). The starting address of the block of
data to be transmitted could easily be modied by the
program.
FIGURE 6-10: INDIRECT ADDRESSING
Opcode
Address
File = INDFx
FSR
Instruction
Executed
Instruction
Fetched
RAM
Opcode
File
相关PDF资料
PDF描述
PIC17C766T-33E/L 8-BIT, OTPROM, 33 MHz, RISC MICROCONTROLLER, PQCC84
PIC18C242-I/SO 8-BIT, OTPROM, 40 MHz, RISC MICROCONTROLLER, PDSO28
PIC18C442-E/L 8-BIT, OTPROM, 40 MHz, RISC MICROCONTROLLER, PQCC44
PIC18F2515 PIC18FX515/X610 Product Brief
PIC18F2539 PIC18F2539 Motor Control Evaluation Kit
相关代理商/技术参数
参数描述
PIC17C44/JW 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O 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
PIC17C44-16/L 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O 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
PIC17C44-16/P 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O 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
PIC17C44-16/P 制造商:Microchip Technology Inc 功能描述:IC 8-BIT CMOS MCU OTP ((NS))
PIC17C44-16/PQ 功能描述:8位微控制器 -MCU 16KB 454 RAM 33 I/O 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