參數(shù)資料
型號: PIC16C642
廠商: Microchip Technology Inc.
英文描述: 8-Bit EPROM Microcontrollers with Analog Comparators(每個I/O口有25mA驅動/吸收電流,可編程Vref,微控制器)
中文描述: 8位EPROM微控制器與模擬比較器(每個的I / O口有25毫安驅動/吸收電流,可編程Vref的,微控制器)
文件頁數(shù): 32/136頁
文件大?。?/td> 837K
代理商: PIC16C642
PIC16C64X & PIC16C66X
DS30559A-page 32
Preliminary
1996 Microchip Technology Inc.
5.2
PORTB and TRISB Registers
PORTB is an 8-bit wide bi-directional port. The
corresponding data direction register is TRISB. Setting
a bit in the TRISB register puts the corresponding out-
put driver in a hi-impedance mode. Clearing a bit in the
TRISB register puts the contents of the output latch on
the selected pin(s).
Reading PORTB register reads the status of the pins,
whereas writing to it will write to the port latch. All write
operations are read-modify-write operations. There-
fore, a write to a port implies that the port pins are read,
this value is modified, and then written to the port data
latch.
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is
done by clearing the RBPU (OPTION<7>) bit. The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are dis-
abled on a Power-on Reset.
Four of PORTB’s pins, RB7:RB4, have an interrupt on
change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e., any RB7:RB4 pin
configured as an output is excluded from the interrupt
on change comparison). The input pins (of RB7:RB4)
are compared with the old value latched on the last
read of PORTB. The “mismatch” outputs of RB7:RB4
are OR’ed together to generate the RBIF interrupt (flag
latched in (INTCON<0>)).
FIGURE 5-5:
BLOCK DIAGRAM OF
RB7:RB4 PINS
Data Latch
D
From other
RB7:RB4 pins
RBPU
(2)
P
V
DD
I/O
pin
(1)
Q
CK
Q
D
CK
Q
D
EN
Q
D
EN
Data bus
WR Port
WR TRIS
Set RBIF
TRIS Latch
RD TRIS
RD Port
weak
pull-up
RD Port
Latch
TTL
Input
Buffer
Note 1: I/O pins have diode protection to V
DD
and V
SS
.
2: TRISB = '1' enables weak pull-up if RBPU = '0'
(OPTION<7>).
ST
Buffer
RB7:RB6 in serial programming mode
This interrupt can wake the device from SLEEP. The
user, in the interrupt service routine, can clear the
interrupt in the following manner:
a)
Any read or write of PORTB. This will end the
mismatch condition.
b)
Clear flag bit RBIF.
A mismatch condition will continue to set flag bit RBIF.
Reading PORTB will end the mismatch condition, and
allow flag bit RBIF to be cleared.
This interrupt on mismatch feature, together with
software configurable pull-ups on these four pins allow
easy interface to a keypad and make it possible for
wake-up on key-depression. (See AN552 in the
Microchip
Embedded Control Handbook
The interrupt on change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt on change
feature. Polling of PORTB is not recommended while
using the interrupt on change feature.
.)
FIGURE 5-6:
BLOCK DIAGRAM OF
RB3:RB0 PINS
Data Latch
D
RBPU
(2)
P
V
DD
Q
CK
Q
D
CK
Q
D
EN
Data bus
WR Port
WR TRIS
RD TRIS
RD Port
weak
pull-up
RD Port
RB0/INT
I/O
pin
(1)
TTL
Input
Buffer
Note 1: I/O pins have diode protection to V
DD
and V
SS
.
2: TRISB = '1' enables weak pull-up if RBPU = '0'
(OPTION<7>).
ST
Buffer
相關PDF資料
PDF描述
PIC16C64A Using the 8-Bit Parallel Slave Port(每個I/O口有25mA驅動/吸收電流,并行從動口,1路捕捉/比較/PWM的微控制器)
PIC16C66 8-Bit CMOS Microcontrollers(每個I/O口有25mA驅動/吸收電流,1路捕捉/比較/PWM的微控制器)
PIC16C67 8-Bit CMOS Microcontrollers(每個I/O口有25mA驅動/吸收電流,1路捕捉/比較/PWM的微控制器)
PIC16C62 8-Bit CMOS Microcontrollers(每個I/O口有25mA驅動/吸收電流,22個I/O,2.5V的微控制器)
PIC16C62A 8-Bit CMOS Microcontrollers(每個I/O口有25mA驅動/吸收電流,22個I/O,2.5V的微控制器)
相關代理商/技術參數(shù)
參數(shù)描述
PIC16C642/JW 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O 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
PIC16C642-04/SO 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O 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
PIC16C642-04/SP 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O 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
PIC16C642-04E/SO 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O 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
PIC16C642-04E/SP 功能描述:8位微控制器 -MCU 7KB 176 RAM 22 I/O 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