TS80C31X2-VCBB 参数 Datasheet PDF下载

TS80C31X2

XTAL1

XTAL1:2

X2 bit

CPU clock

STD Mode

X2 Mode

STD Mode

Figure 2. Mode Switching Waveforms

The X2 bit in the CKCON register (See Table 3.) allows to switch from 12 clock cycles per instruction to 6 clock

cycles and vice versa. At reset, the standard speed is activated (STD mode). Setting this bit activates the X2 feature

(X2 mode).

CAUTION

In order to prevent any incorrect operation while operating in X2 mode, user must be aware that all peripherals

using clock frequency as time reference (UART, timers) will have their time reference divided by two. For example

a free running timer generating an interrupt every 20 ms will then generate an interrupt every 10 ms. UART with

4800 baud rate will have 9600 baud rate.

Rev. A - Mar. 19, 1999

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Preliminary