MC80F0804D View Datasheet(PDF) - Unspecified

Part Name

Description

Manufacturer

MC80F0804D

8-BIT SINGLE-CHIP MICROCONTROLLERS

Unspecified 

MC80F0704/0708/0804/0808

15.2 The usage of Serial I/O

1. Select transmission/receiving mode.

2. In case of sending mode, write data to be send to SIOR.

3. Set SIOST to “1” to start serial transmission.

4. The SIO interrupt is generated at the completion of SIO

and SIOIF is set to “1”.

5. In case of receiving mode, the received data is acquired

by reading the SIOR.

6. When using polling method, the completion of 1 byte

serial communication can be checked by reading

SIOST and SIOSF. As shown in example code, wait un-

til SIOST is changed to “0” and then wait the SIOSF is

changed to “1” for completion check.

LDM SIOR,#0AAh

;set tx data

LDM SIOM,#0011_1100b;set SIO mode

NOP

LDM SIOM,#0011_1110b;SIO Start

NOP

SIO_WAIT:

NOP

BBS SIOST,SIO_WAIT ;wait first edge

BBC SIOSF,SIO_WAIT ;wait complete

Note: When external clock is used, the frequency should be less

than 1MHz and recommended duty is 50%. If both transmission

mode is selected and transmission is performed simultaneously,

error may be occur.

76

October 31, 2011 Ver 1.03

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