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: 35/71页
文件大小: 1173K
代理商: PIC17C44
PIC17C4X
DS30412C-page 40
1996 Microchip Technology Inc.
6.4.1
INDIRECT ADDRESSING REGISTERS
The PIC17C4X has four registers for indirect address-
ing. These registers are:
INDF0 and FSR0
INDF1 and FSR1
Registers INDF0 and INDF1 are not physically imple-
mented. Reading or writing to these registers activates
indirect addressing, with the value in the correspond-
ing FSR register being the address of the data. The
FSR is an 8-bit register and allows addressing any-
where in the 256-byte data memory address range.
For banked memory, the bank of memory accessed is
specied by the value in the BSR.
If le INDF0 (or INDF1) itself is read indirectly via an
FSR, all '0's are read (Zero bit is set). Similarly, if
INDF0 (or INDF1) is written to indirectly, the operation
will be equivalent to a NOP, and the status bits are not
affected.
6.4.2
INDIRECT ADDRESSING OPERATION
The indirect addressing capability has been enhanced
over that of the PIC16CXX family. There are two con-
trol bits associated with each FSR register. These two
bits congure the FSR register to:
Auto-decrement the value (address) in the FSR
after an indirect access
Auto-increment the value (address) in the FSR
after an indirect access
No change to the value (address) in the FSR after
an indirect access
These control bits are located in the ALUSTA register.
The FSR1 register is controlled by the FS3:FS2 bits
and FSR0 is controlled by the FS1:FS0 bits.
When using the auto-increment or auto-decrement
features, the effect on the FSR is not reected in the
ALUSTA register. For example, if the indirect address
causes the FSR to equal '0', the Z bit will not be set.
If the FSR register contains a value of 0h, an indirect
read will read 0h (Zero bit is set) while an indirect write
will be equivalent to a NOP (status bits are not
affected).
Indirect addressing allows single cycle data transfers
within the entire data space. This is possible with the
use of the MOVPF and MOVFP instructions, where either
'p' or 'f' is specied as INDF0 (or INDF1).
If the source or destination of the indirect address is in
banked memory, the location accessed will be deter-
mined by the value in the BSR.
A simple program to clear RAM from 20h - FFh is
shown in Example 6-1.
EXAMPLE 6-1:
INDIRECT ADDRESSING
MOVLW
0x20
;
MOVWF
FSR0
; FSR0 = 20h
BCF
ALUSTA, FS1
; Increment FSR
BSF
ALUSTA, FS0
; after access
BCF
ALUSTA, C
; C = 0
MOVLW
END_RAM + 1
;
LP
CLRF
INDF0
; Addr(FSR) = 0
CPFSEQ
FSR0
; FSR0 = END_RAM+1?
GOTO
LP
; NO, clear next
:
; YES, All RAM is
:
; cleared
6.5
Table Pointer (TBLPTRL and
TBLPTRH)
File registers TBLPTRL and TBLPTRH form a 16-bit
pointer to address the 64K program memory space.
The table pointer is used by instructions TABLWT and
TABLRD
.
The TABLRD and the TABLWT instructions allow trans-
fer of data between program and data space. The table
pointer serves as the 16-bit address of the data word
within the program memory. For a more complete
description of these registers and the operation of Table
Reads and Table Writes, see Section 7.0.
6.6
Table Latch (TBLATH, TBLATL)
The table latch (TBLAT) is a 16-bit register, with
TBLATH and TBLATL referring to the high and low
bytes of the register. It is not mapped into data or pro-
gram memory. The table latch is used as a temporary
holding latch during data transfer between program and
data memory (see descriptions of instructions TABLRD,
TABLWT
, TLRD and TLWT). For a more complete
description of these registers and the operation of Table
Reads and Table Writes, see Section 7.0.
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