CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Serial Interface)

During receiving

The received data is stored.

When "1" is read: High level

When "0" is read: Low level

The data from the receive data buffer can be read out.

Since the sift register is provided separately from this buffer, reading can be done during a receive operation in the asynchronous mode. (The buffer function is not used in the clock synchronous mode.)

Read the data after waiting for a receive completion interrupt.

When performing parity check in the 7-bit asynchronous mode, "0" is loaded into the 8th bit (TRXD7/ TRXD7S) that corresponds to the parity bit.

The serial data input from the SIN terminal is level converted, making the High (VDD) level bit "1" and the Low (VSS) level bit "0" and is then loaded into this buffer.

At initial reset, the buffer content is undefined.

OER: Serial interface (1) overrun error flag (FF73H•D0)OERS: Serial interface (2) overrun error flag (FF5BH•D0)

Indicates the generation of an overrun error.

When "1" is read: Error

When "0" is read: No error

When "1" is written: Reset to "0"

When "0" is written: Invalid

OER/OERS is an error flag that indicates the generation of an overrun error and becomes "1" when an error has been generated.

An overrun error is generated when a receiving of data has completed prior to writing "1" to RXTRG/ RXTRGS in the asynchronous mode.

OER/OERS is reset to "0" by writing "1".

OER/OERS is set to "0" at initial reset or when RXEN/RXENS is set to "0".

PER: Serial interface (1) parity error flag (FF73H•D1)PERS: Serial interface (2) parity error flag (FF5BH•D1)

Indicates the generation of a parity error.

When "1" is read: Error

When "0" is read: No error

When "1" is written: Reset to "0"

When "0" is written: Invalid

PER/PERS is an error flag that indicates the generation of a parity error and becomes "1" when an error has been generated.

When a parity check is performed in the asynchronous mode, a parity error will be generated if data that does not match the parity is received.

PER/PERS is reset to "0" by writing "1".

PER/PERS is set to "0" at initial reset or when RXEN/RXENS is set to "0".

S1C63558 TECHNICAL MANUAL

EPSON

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