ATA8743-PXQW【PDF 73/238 页】MCU W/TRANSMITTER ASK/FSK 24QFN

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52

69页 70页 71页 72页 [73页]74页 75页 76页 77页

9152BINDCO02/10

ATA8743

Note that enabling the alternate function of some of the port pins does not affect the use of the

other pins in the port as general digital I/O.

19.2 Ports as General Digital I/O

The ports are bi-directional I/O ports with optional internal pull-ups. Figure 19-2 shows a func-

tional description of one I/O-port pin, here generically called Pxn.

Figure 19-2. General Digital I/O

(1)

Note:

1. WRx, WPx, WDx, RRx, RPx, and RDx are common to all pins within the same port. clk

I/O

SLEEP , and PUD are common to all ports.

19.2.1

Configuring the Pin

Each port pin consists of three register bits: DDxn, PORTxn, and PINxn. As shown in

EXT_CLOCK = external clock is selected as system clock. on page 86, the DDxn bits are

accessed at the DDRx I/O address, the PORTxn bits at the PORTx I/O address, and the PINxn

bits at the PINx I/O address.

The DDxn bit in the DDRx Register selects the direction of this pin. If DDxn is written logic one,

Pxn is configured as an output pin. If DDxn is written logic zero, Pxn is configured as an input

pin.

If PORTxn is written logic one when the pin is configured as an input pin, the pull-up resistor is

activated. To switch the pull-up resistor off, PORTxn has to be written logic zero or the pin has to

be configured as an output pin. The port pins are tri-stated when reset condition becomes active,

even if no clocks are running.

clk

RPx

RRx

RDx

WDx

PUD

SYNCHRONIZER

WDx:

WRITE DDRx

WRx:

WRITE PORTx

RRx:

READ PORTx REGISTER

RPx:

READ PORTx PIN

PUD:

PULLUP DISABLE

clk

I/O

I/O CLOCK

RDx:

READ DDRx

RESET

CLR

PORTxn

CLR

DDxn

PINxn

SLEEP

SLEEP:

SLEEP CONTROL

Pxn

I/O

WPx

WRx

WPx:

WRITE PINx REGISTER

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