Flags Indicating The Status Of Csio Receive Operation - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

12.4.5 Flags Indicating the Status of CSIO Receive Operation

Following flags are available that indicate the status of receive operation in CSIO mode.

• SIO Receive Control Register receive status bit

• SIO Receive Control Register receive-finished bit

• SIO Receive Control Register receive error bit

• SIO Receive Control Register overrun error bit

After reception is completed, you may read out the content of the SIO Receive Buffer Register, but

if the serial I/O finishes receiving the next data before you read, an overrun error occurs. In this

case, the data received thereafter is not transferred to the SIO Receive Buffer Register. To restart

reception, temporarily clear the receive enable bit to 0 and initialize the receive control block before

you restart.

The said receive enable bit can be cleared, when there are no receive errors(note) encountered, by

reading the lower byte from the SIO Receive Buffer Register or clearing the REN (receive enable)

bit. If any receive error has occurred, it can only be cleared by clearing the REN (receive enable) bit,

and cannot be cleared by reading the lower byte from the SIO Receive Buffer Register.

Note : Overrun error is the only error that can be detected during reception in CSIO mode.

12.4 Receive Operation in CSIO Mode