NO:
W90P710 Programming Guide
VERSION:
2.0
PAGE:
147
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed, distributed or reproduced without permission
from Winbond.
Table No.: 2005-W90P710-11-A
11.3.3 Polled
I/O
Functions
The driver can transmit and receive data through UART by polling mode. The poll functions check
UART buffer by reading status register. If there’s at least one data byte available in receive FIFO, the
[RFDR] bit is set 1. It indicates that driver can read receive FIFO to get new data bytes. If the
transmitter is empty, the [TE] bit is set 1. Then the data bytes can be written into the transmit FIFO.
The data bytes in the transmit FIFO will be shifted to SOUT serially. Figure 11-2 and Figure 11-3
show the programming flow of transmit data and receive data in polling mode.
Figure 11-2 Transmit data in polling mode
Start
End
Read LSR
TE== 1 ?
Write 16 data bytes to THR
Y
N
