PIC16F737-I/SP【PDF 136/231 页】IC PIC MCU FLASH 4KX14 28DIP

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录3841

132页 133页 134页 135页 [136页]137页 138页 139页 140页

PIC18F2X1X/4X1X

DS39636D-page 226

2009 Microchip Technology Inc.

FIGURE 19-3:

COMPARATOR OUTPUT BLOCK DIAGRAM

19.6

Comparator Interrupts

The comparator interrupt flag is set whenever there is

a change in the output value of either comparator.

Software will need to maintain information about the

status of the output bits, as read from CMCON<7:6>, to

determine the actual change that occurred. The CMIF

bit (PIR2<6>) is the Comparator Interrupt Flag. The

CMIF bit must be reset by clearing it. Since it is also

possible to write a ‘1’ to this register, a simulated

interrupt may be initiated.

Both the CMIE bit (PIE2<6>) and the PEIE bit

(INTCON<6>) must be set to enable the interrupt. In

addition, the GIE bit (INTCON<7>) must also be set. If

any of these bits are clear, the interrupt is not enabled,

though the CMIF bit will still be set if an interrupt

condition occurs.

The user, in the Interrupt Service Routine, can clear the

interrupt in the following manner:

Any read or write of CMCON will end the

mismatch condition.

Clear flag bit CMIF.

A mismatch condition will continue to set flag bit CMIF.

Reading CMCON will end the mismatch condition and

allow flag bit CMIF to be cleared.

19.7

Comparator Operation

During Sleep

When a comparator is active and the device is placed

in Sleep mode, the comparator remains active and the

interrupt is functional if enabled. This interrupt will

wake-up the device from Sleep mode, when enabled.

Each operational comparator will consume additional

current, as shown in the comparator specifications. To

minimize power consumption while in Sleep mode, turn

off the comparators (CM2:CM0 = 111) before entering

Sleep. If the device wakes up from Sleep, the contents

of the CMCON register are not affected.

19.8

Effects of a Reset

A device Reset forces the CMCON register to its Reset

state, causing the comparator modules to be turned off

(CM2:CM0 = 111). However, the input pins (RA0

through RA3) are configured as analog inputs by

default on device Reset. The I/O configuration for these

pins is determined by the setting of the PCFG3:PCFG0

bits (ADCON1<3:0>). Therefore, device current is

minimized when analog inputs are present at Reset

time.

To RA4 or

RA5 pin

Bus

Data

Set

MUL

CMIF

bit

Port pins

Read CMCON

Reset

From

other

Comparator

CxINV

Note:

If a change in the CMCON register

(C1OUT or C2OUT) should occur when a

read operation is being executed (start of

the Q2 cycle), then the CMIF (PIR

registers) interrupt flag may not get set.

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式