AT87251G2D-3CSUM【PDF 77/77 页】IC 8051 MCU 32K OTP 24MHZ 40DIP

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3833

73页 74页 75页 76页 [77页]

AT/TSC8x251G2D

4135F–8051–11/06

T1:0

I/O

Timer 1:0 External Clock Inputs

When timer 1:0 operates as a counter, a falling edge on the T1:0 pin

increments the count.

–

I/O

Timer 2 Clock Input/Output

For the timer 2 capture mode, T2 is the external clock input. For the Timer 2

clock-out mode, T2 is the clock output.

P1.0

T2EX

Timer 2 External Input

In timer 2 capture mode, a falling edge initiates a capture of the timer 2

registers. In auto-reload mode, a falling edge causes the timer 2 register to

be reloaded. In the up-down counter mode, this signal determines the

count direction: 1 = up, 0 = down.

P1.1

TXD

Transmit Serial Data

TXD outputs the shift clock in serial I/O mode 0 and transmits data in serial

I/O modes 1, 2 and 3.

P3.1

VDD

PWR

Digital Supply Voltage

Connect this pin to +5V or +3V supply voltage.

–

VPP

Programming Supply Voltage

The programming supply voltage is applied to this input for programming

the on-chip EPROM/OTPROM.

–

VSS

GND

Circuit Ground

Connect this pin to ground.

–

VSS1

GND

Secondary Ground 1

This ground is provided to reduce ground bounce and improve power

supply bypassing. Connection of this pin to ground is recommended.

However, when using the TSC80251G2D as a pin-for-pin replacement for a

8xC51 product, VSS1 can be unconnected without loss of compatibility.

Not available on DIP package.

–

VSS2

GND

Secondary Ground 2

This ground is provided to reduce ground bounce and improve power

supply bypassing. Connection of this pin to ground is recommended.

However, when using the TSC80251G2D as a pin-for-pin replacement for a

8xC51 product, VSS2 can be unconnected without loss of compatibility.

Not available on DIP package.

–

WAIT#

Real-time Synchronous Wait States Input

The real-time WAIT# input is enabled by setting RTWE bit in WCON

(S:A7h). During bus cycles, the external memory system can signal

‘system ready’ to the microcontroller in real time by controlling the WAIT#

input signal.

P1.6

WCLK

Wait Clock Output

The real-time WCLK output is enabled by setting RTWCE bit in WCON

(S:A7h). When enabled, the WCLK output produces a square wave signal

with a period of one half the oscillator frequency.

P1.7

WR#

Write

Write signal output to external memory.

P3.6

XTAL1

Input to the on-chip inverting oscillator amplifier

To use the internal oscillator, a crystal/resonator circuit is connected to this

pin. If an external oscillator is used, its output is connected to this pin.

XTAL1 is the clock source for internal timing.

–

Table 2.

Product Name Signal Description (Continued)

Signal

Name

Type

Description

Alternate

Function

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