參數(shù)資料
型號: PIC16C505
廠商: Microchip Technology Inc.
英文描述: 14-Pin, 8-Bit CMOS Microcontroller(每個I/O口有25mA驅(qū)動/吸收電流,12個I/O口,帶WDT的微控制器)
中文描述: 14引腳,8位CMOS微控制器(每個的I / O口有25毫安驅(qū)動/吸收電流,12個的I / O口,帶看門狗的微控制器)
文件頁數(shù): 20/80頁
文件大?。?/td> 617K
代理商: PIC16C505
PIC16C505
DS40192A-page 20
Preliminary
1998 Microchip Technology Inc.
TABLE 5-1:
SUMMARY OF PORT REGISTERS
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2 Bit 1 Bit 0
Value on
Power-On
Reset
Value on
MCLR and
WDT Reset
Value on
Wake-up on
Pin Change
N/A
TRISB
I/O control registers
--11 1111
--11 1111
--11 1111
N/A
TRISC
I/O control registers
--11 1111
--11 1111
--11 1111
N/A
OPTION
RBWU
RBPU
TOCS
TOSE
PSA
PS2
PS1
PS0
1111 1111
1111 1111
1111 1111
03h
STATUS
RBWUF
PAO
TO
PD
Z
DC
C
0001 1xxx
000q quuu
100q quuu
06h
PORTB
RB5
RB4
RB3
RB2
RB1
RB0
--xx xxxx --uu uuuu
--uu uuuu
07h
PORTC
RC5
RC4
RC3
RC2
RC1
RC0
--xx xxxx --uu uuuu
--uu uuuu
Legend: Shaded cellls not used by Port Registers, read as ‘0’,
= unimplemented, read as ‘0’, x = unknown, u = unchanged.
5.5
I/O Programming Considerations
5.5.1
BI-DIRECTIONAL I/O PORTS
Some instructions operate internally as read followed
by write operations. The
BCF
and
BSF
instructions, for
example, read the entire port into the CPU, execute
the bit operation and re-write the result. Caution must
be used when these instructions are applied to a port
where one or more pins are used as input/outputs. For
example, a
BSF
operation on bit5 of PORTB will cause
all eight bits of PORTB to be read into the CPU, bit5 to
be set and the PORTB value to be written to the output
latches. If another bit of PORTB is used as a bi-
directional I/O pin (say 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, overwriting the
previous content. As long as the pin stays in the input
mode, no problem occurs. However, if bit0 is switched
into output mode later on, the content of the data latch
may now be unknown.
Example 5-1 shows the effect of two sequential read-
modify-write instructions (e.g.,
BCF, BSF
, etc.) on an I/
O port.
A pin actively outputting a high or a low 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.
EXAMPLE 5-1:
READ-MODIFY-WRITE
INSTRUCTIONS ON AN
I/O PORT
;Initial PORTB Settings
; PORTB<5:3> Inputs
; PORTB<2:0> Outputs
;
; PORTB latch PORTB pins
; ---------- ----------
BCF PORTB, 5 ;--01 -ppp --11 pppp
BCF PORTB, 4 ;--10 -ppp --11 pppp
MOVLW 007h ;
TRIS PORTB ;--10 -ppp --11 pppp
;
;Note that the user may have expected the pin
;values to be --00 pppp. The 2nd BCF caused
;RB5 to be latched as the pin value (High).
5.5.2
SUCCESSIVE OPERATIONS ON I/O
PORTS
The actual write to an I/O port happens at the end of
an instruction cycle, whereas for reading, the data
must be valid at the beginning of the instruction cycle
(Figure 5-2). Therefore, care must be exercised if a
write followed by a read operation is carried out on the
same I/O port. The sequence of instructions should
allow the pin voltage to stabilize (load dependent)
before the next instruction, which causes that file to be
read into the CPU, is executed. Otherwise, the
previous state of that pin may be read into the CPU
rather than the new state. When in doubt, it is better to
separate these instructions with a
NOP
or another
instruction not accessing this I/O port.
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參數(shù)描述
PIC16C505/JW 功能描述:8位微控制器 -MCU 1.5KB 72 RAM 12 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(fēng)格:SMD/SMT
PIC16C505-04/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(fēng)格:SMD/SMT
PIC16C505-04/P 制造商:Microchip Technology Inc 功能描述:IC 8BIT CMOS MCU (TUBE 30) 16C505 制造商:Microchip Technology Inc 功能描述:IC 8BIT CMOS MCU 16C505 DIP14
PIC16C505-04/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(fēng)格:SMD/SMT
PIC16C505-04/SL 制造商:Microchip Technology Inc 功能描述:8BIT CMOS MCU SMD 16C505 SOIC14