IA186EM-PQF100I-R datasheet(23/133 Pages) INNOVASIC

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IA186EM/IA188EM

Data Sheet

8/16-BIT Microcontrollers

As of Production Version -03

SPRD (086h) - Serial Port Receive Data Register.

Data received over the serial port are stored in this register until read. The data are received initially by

the receive shift register (no software access) permitting data to be received while the previous data are

being read.

The RDR bit (Receive Data Ready) in the serial port status register indicates the status of the SPRD

The value of the SPRD register is undefined at reset.

5 4 3

Reserved

RDATA

Reserved (bits 15-8) – Reserved.

RDATA [7:0] (bits 7-0) – Holds valid data while the RDR bit of the status register is set.

SPTD (084h) - Serial Port Transmit Data Register.

Data is written to this register by software, with the values to be transmitted by the serial port. Double

buffering of the transmitter allows for the transmission of data from the transmit shift register (no

software access), while the next data are written into the transmit register.

The THRE bit in the Serial Port Status register indicates whether there is valid data in the SPDT register.

The THRE bit must be a 1 before writing data to this register to prevent overwriting valid data that is

already in the SPDT register.

The value of the SPTD register is undefined at reset.

5 4 3

Reserved

TDATA

Reserved (bits 15-8) – Reserved.

TDATA [7:0] (bits 7-0) – Holds the data to be transmitted.

SPSTS (082h) – Serial Port STatuS Register.

This register stores information concerning the current status of the port. The status bits are described

below.

The value of the SPSTS register is undefined at reset.

12 11 10 9

Reserved

TEMT THRE RDR BRKI

FER

PER OER

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IA186EM-PQF100I-R датащи(PDF) 23 Page - InnovASIC, Inc