參數(shù)資料
型號(hào)： PIC16LCE625T-04E/SS
廠商： Microchip Technology
文件頁(yè)數(shù)： 33/100頁(yè)
文件大?。?/td> 0K
描述： IC MCU CMOS 2K OTP W/EEPRM20SSOP
標(biāo)準(zhǔn)包裝： 1,600
系列： PIC® 16C
核心處理器： PIC
芯體尺寸： 8-位
速度： 4MHz
外圍設(shè)備： 欠壓檢測(cè)/復(fù)位，POR，WDT
輸入/輸出數(shù)： 13
程序存儲(chǔ)器容量： 3.5KB（2K x 14）
程序存儲(chǔ)器類(lèi)型： OTP
EEPROM 大?。?/td> 128 x 8
RAM 容量： 128 x 8
電壓 - 電源 (Vcc/Vdd)： 2.5 V ~ 5.5 V
振蕩器型： 外部
工作溫度： -40°C ~ 125°C
封裝/外殼： 20-SSOP（0.209"，5.30mm 寬）
包裝： 帶卷 (TR)
其它名稱： PIC16LCE625T04ESS
PIC16CE62X
DS40182C-page 28
1999 Microchip Technology Inc.
5.3
I/O Programming Considerations
5.3.1
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 PORTB will cause all eight bits of PORTB to be read
into the CPU. Then the BSF operation takes place on
bit5 and PORTB is written to the output latches. If
another bit of PORTB is used as a bidirectional 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 re-written 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.
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 5-2 shows the effect of two sequential
read-modify-write instructions (i.e., BCF, BSF, etc.) on
an I/O port.
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.
EXAMPLE 5-2:
READ-MODIFY-WRITE
INSTRUCTIONS ON AN
I/O PORT
5.3.2
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 5-7). 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 causes that file to be read
into the CPU. 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 instruc-
tions with an NOP or another instruction not accessing
this I/O port.
;
Initial PORT settings:
PORTB<7:4> Inputs
;
PORTB<3:0> Outputs
;
PORTB<7:6> have external pull-up and are not
connected to other circuitry
;
PORT latch
PORT pins
;
----------
BCF PORTB, 7
; 01pp pppp
11pp pppp
BCF PORTB, 6
; 10pp pppp
11pp pppp
BSF STATUS,RP0
;
BCF TRISB, 7
; 10pp pppp
11pp pppp
BCF TRISB, 6
; 10pp pppp
10pp pppp
;
; Note that the user may have expected the pin
; values to be 00pp pppp. The 2nd BCF caused
; RB7 to be latched as the pin value (High).
FIGURE 5-7:
SUCCESSIVE I/O OPERATION
Note:
This example shows write to PORTB
followed by a read from PORTB.
Note that:
data setup time = (0.25 TCY - TPD)
where TCY = instruction cycle and
TPD = propagation delay of Q1 cycle
to output valid.
Therefore, at higher clock frequencies,
a write followed by a read may be
problematic.
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
RB <7:0>
Port pin
sampled here
PC
PC + 1
PC + 2
PC + 3
NOP
MOVF PORTB, W
Read PORTB
MOVWF PORTB
Write to
PORTB
PC
Instruction
fetched
TPD
Execute
MOVWF
PORTB
Execute
MOVF
PORTB, W
Execute
NOP
RB<7:0>
PC
Instruction
Fetched
相關(guān)PDF資料
PDF描述
1-84981-2 CONN FFC 12POS 1.00MM R/A SMD
PIC16LCE625T-04E/SO IC MCU CMOS 2K OTP W/EEPRM18SOIC
1-84534-8 CONN FFC 18POS 1.25MM VERT
PIC18C452T-E/PT IC MCU OTP 16KX16 A/D 44TQFP
PIC18C242T-E/SO IC MCU OTP 8KX16 A/D 28SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC16LCE625T-04I/SO 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 13 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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
PIC16LCE625T-04I/SS 功能描述:8位微控制器 -MCU 3.5KB 128 RAM 13 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(shí)鐘頻率:50 MHz 程序存儲(chǔ)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
PIC16LF1454-E/ML 制造商:Microchip Technology Inc 功能描述:7 KB FLASH, 512 BYTES RAM, 48 MHZ INT. OSC, 12 I/0, ENHANCED - Rail/Tube 制造商:Microchip Technology Inc 功能描述:IC MCU 8BIT 7KB FLASH 16QFN 制造商:Microchip Technology Inc 功能描述:8-bit Microcontrollers - MCU 7KB Flsh 512b RAM 48MHz Int Osc 12 I/0
PIC16LF1454-E/P 制造商:Microchip Technology Inc 功能描述:7 KB FLASH, 512 BYTES RAM, 48 MHZ INT. OSC, 12 I/0, ENHANCED - Rail/Tube 制造商:Microchip Technology Inc 功能描述:IC MCU 8BIT 7KB FLASH 14PDIP
PIC16LF1454-E/SL 制造商:Microchip Technology Inc 功能描述:7 KB FLASH, 512 BYTES RAM, 48 MHZ INT. OSC, 12 I/0, ENHANCED - Rail/Tube 制造商:Microchip Technology Inc 功能描述:7 KB Flash, 512 bytes RAM, 48 MHz Int. Osc, 12 I/0, Enhanced Mid Range Core, USB 2.0, NanoWatt XLP
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*