
V PeRiPheRaL MoDuLes 3 (inteRFaCe): GeneRaL-PuRPose seRiaL inteRFaCe (eFsio)
V-1-44
ePson
s1C33L17 teChniCaL ManuaL
D3
PeRx: serial i/F Ch.x Parity error Flag
Indicates whether a parity error occurred.
1 (R):
An error occurred
0 (R):
No error occurred (default)
1 (W):
Has no effect
0 (W):
Reset to 0
PERx is an error flag indicating whether a parity error occurred. When an error has occurred, it is set to 1.
Parity checks are valid only in ISO7816 mode or asynchronous mode with EPRx set to 1 (parity added).
This check is performed when the received data is transferred from the shift register to the receive data
buffer.
PERx is reset by writing 0 or when RXENx and TXENx both are set to 0.
D2
oeRx: serial i/F Ch.x overrun error Flag
Indicates whether an overrun error occurred.
1 (R):
An error occurred
0 (R):
No error occurred (default)
1 (W):
Has no effect
0 (W):
Reset to 0
OERx is an error flag indicating whether an overrun error occurred. When an error has occurred, it is set
to 1. An overrun error will occur if a new data is transferred to this serial interface when the receive data
buffer is full and also the shift register contains received data. When this error occurs, the shift register
is overwritten with the new received data and the receive data in the buffer is maintained as is.
OERx is reset by writing 0 or when RXENx and TXENx both are set to 0.
D1
tDBex: serial i/F Ch.x transmit Data Buffer empty Flag
Indicates the status of the transmit data buffer.
1 (R):
Not full (default)
0 (R):
Buffer full
TDBEx is set to 1 when the transmit data buffer has a free space for transmit data to be written and reset
to 0 when the transmit data buffer becomes full by writing transmit data.
Up to two transmit data can be written to the transmit data buffer.
D0
RDBFx: serial i/F Ch.x Receive Data Buffer Full Flag
Indicates the status of the receive data buffer.
1 (R):
Not empty
0 (R):
Buffer empty (default)
RDBFx is set to 1 when the receive data buffer contains one or more received data, and is reset to 0
when the receive data buffer becomes empty by reading all the received data.