参数资料
型号: ENC424J600T-I/ML
厂商: Microchip Technology
文件页数: 116/168页
文件大小: 0K
描述: IC ETHERNET CTRLR W/SPI 44-QFN
视频文件: Fast 100 Mbps Ethernet PICtail Plus Overview
标准包装: 1,600
控制器类型: 以太网控制器(IEEE 802.3)
接口: SPI
电源电压: 3 V ~ 3.6 V
电流 - 电源: 96mA
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 44-VQFN 裸露焊盘
供应商设备封装: 44-QFN(8x8)
包装: 带卷 (TR)
配用: AC164132-ND - BOARD DAUGHTER PICTAIL ETHERNET
2007 Microchip Technology Inc.
DS21993C-page 49
PIC16CR7X
6.4
Timer1 Operation in
Asynchronous Counter Mode
If control bit T1SYNC (T1CON<2>) is set, the external
clock input is not synchronized. The timer continues to
increment asynchronous to the internal phase clocks.
The timer will continue to run during Sleep and can
generate an interrupt on overflow, which will wake-up
the processor. However, special precautions in soft-
ware are needed to read/write the timer (Section 6.4.1
In Asynchronous Counter mode, Timer1 cannot be
used as a time base for capture or compare operations.
6.4.1
READING AND WRITING TIMER1 IN
ASYNCHRONOUS COUNTER
MODE
Reading TMR1H or TMR1L, while the timer is running
from an external asynchronous clock, will ensure a
valid read (taken care of in hardware). However, the
user should keep in mind that reading the 16-bit timer
in two 8-bit values itself, poses certain problems, since
the timer may overflow between the reads.
For writes, it is recommended that the user simply stop
the timer and write the desired values. A write conten-
tion may occur by writing to the timer registers, while
the register is incrementing. This may produce an
unpredictable value in the timer register.
Reading the 16-bit value requires some care. The
example
code
provided
in
and
Example 6-2 demonstrates how to write to and read
Timer1 while it is running in Asynchronous mode.
EXAMPLE 6-1:
WRITING A 16-BIT FREE-RUNNING TIMER
EXAMPLE 6-2:
READING A 16-BIT FREE-RUNNING TIMER
; All interrupts are disabled
CLRF
TMR1L
; Clear Low byte, Ensures no rollover into TMR1H
MOVLW
HI_BYTE
; Value to load into TMR1H
MOVWF
TMR1H, F
; Write High byte
MOVLW
LO_BYTE
; Value to load into TMR1L
MOVWF
TMR1H, F
; Write Low byte
; Re-enable the Interrupt (if required)
CONTINUE
; Continue with your code
; All interrupts are disabled
MOVF
TMR1H, W
; Read high byte
MOVWF
TMPH
MOVF
TMR1L, W
; Read low byte
MOVWF
TMPL
MOVF
TMR1H, W
; Read high byte
SUBWF
TMPH,
W
; Sub 1st read with 2nd read
BTFSC
STATUS,Z
; Is result = 0
GOTO
CONTINUE
; Good 16-bit read
; TMR1L may have rolled over between the read of the high and low bytes.
; Reading the high and low bytes now will read a good value.
MOVF
TMR1H, W
; Read high byte
MOVWF
TMPH
MOVF
TMR1L, W
; Read low byte
MOVWF
TMPL
; Re-enable the Interrupt (if required)
CONTINUE
; Continue with your code
相关PDF资料
PDF描述
PIC16F677-E/P IC PIC MCU FLASH 2KX14 20DIP
MCP2155-I/P IC IRDA PROTOCOL CTRLR 18DIP
MCP2150T-I/SS IC IRDA STD CONTROLLER 20SSOP
MCP2155T-I/SO IC IRDA PROTOCOL CONTRLR 18-SOIC
PIC18F25J10T-I/SS IC PIC MCU FLASH 16KX16 28SSOP
相关代理商/技术参数
参数描述
ENC424J600T-IPT 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:Stand-Alone 10/100 Ethernet Controller with SPI or Parallel Interface
ENC431D05A 制造商:未知厂家 制造商全称:未知厂家 功能描述:
ENC431D-05A 制造商:未知厂家 制造商全称:未知厂家 功能描述:STD MOV
ENC431D07A 制造商:未知厂家 制造商全称:未知厂家 功能描述:
ENC431D-07A 制造商:未知厂家 制造商全称:未知厂家 功能描述:STD MOV