參數(shù)資料
型號: PIC16LC433E/P
元件分類: 微控制器/微處理器
英文描述: 8-BIT, OTPROM, 4 MHz, RISC MICROCONTROLLER, PDIP18
封裝: 0.300 INCH, PLASTIC, DIP-18
文件頁數(shù): 50/122頁
文件大小: 1862K
代理商: PIC16LC433E/P
2001 Microchip Technology Inc.
Advance Information
DS41139A-page 31
PIC16C433
5.5
I/O Programming Considerations
5.5.1
BI-DIRECTIONAL I/O PORTS
Any instruction which writes, operates internally as a
read followed by a write operation. The BCF and BSF
instructions, for example, read the register into the
CPU, execute the bit operation and write the result
back to the register. Caution must be used when these
instructions are applied to a port with both inputs and
outputs defined. For example, a BSF operation on bit5
of GPIO will cause all eight bits of GPIO to be read into
the CPU. Then, the BSF operation takes place on bit5
and GPIO is written to the output latches. If another bit
of GPIO is used as a bi-directional I/O pin (i.e., bit0) and
it is defined as an input at this time, the input signal
present on the pin itself would be read into the CPU and
rewritten to the data latch of this particular pin, overwrit-
ing the previous content. As long as the pin stays in the
input mode, no problem occurs. However, if bit0 is
switched to an output, the content of the data latch may
now be unknown.
Reading the port register reads the values of the port
pins. Writing to the port register writes the value to the
port latch. When using read-modify-write instructions
(i.e., BCF, BSF, etc.) on a port, the value of the port
pins is read, the desired operation is done to this value,
and this value is then written to the port latch.
Example 5-1 shows the effect of two sequential read-
modify-write instructions on an I/O port.
EXAMPLE 5-1:
READ-MODIFY-WRITE
INSTRUCTIONS ON AN
I/O PORT
;Initial GPIO Settings
; GPIO<5:3> Inputs
; GPIO<2:0> Outputs
;
GPIO latch
GPIO pins
;
----------
BCF
GPIO, 5
;--01 -ppp
--11 pppp
BCF
GPIO, 4
;--10 -ppp
--11 pppp
MOVLW 007h
;
TRIS
GPIO
;--10 -ppp
--10 pppp
;
;Note that the user may have expected the pin
;values to be --00 pppp. The 2nd BCF caused
;GP5 to be latched as the pin value (High).
A pin actively outputting a Low or High should not be
driven from external devices at the same time, in order
to change the level on this pin (“wired-or”, “wired-and”).
The resulting high output currents may damage the
chip.
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相關代理商/技術參數(shù)
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PIC16LC433-I/P 功能描述:8位微控制器 -MCU 10MHz 2K EPROM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC16LC433-I/SO 功能描述:8位微控制器 -MCU 10MHz 2K EPROM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC16LC433T-I/SO 功能描述:8位微控制器 -MCU 10MHz 2K EPROM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC16LC505-04/P 功能描述:8位微控制器 -MCU 1.5KB 72 RAM 12 I/O 4MHz PDIP14 RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT
PIC16LC505-04/SL 功能描述:8位微控制器 -MCU 1.5KB 72 RAM 12 I/O 4MHz SOIC14 RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風格:SMD/SMT