W925EP01 Datasheet, PDF (60/108 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925EP01/ W925EP01FG
REN1: Set REN1 from 0 to 1 to start the serial port to receive 8-bit serial data.
SFQ: SFQ=0 Serial clock output frequency is equal to fosc /2
SFQ=1 Serial clock output frequency is equal to fosc /256
SEDG: SEDG=0 Serial data latched at falling edge of clock, SCLK=Low initially.
SEDG=1 Serial data latched at rising edge of clock, SCLK=High initially
CLKIO: CLKIO=0 P4.0 (SCLK) work as output mode
CLKIO=1 P4.0 (SCLK) work as input mode
SIO: SIO=0 P4.0 & P4.1 work as normal I/O pin
SIO=1 P4.0 & P4.1 work as Serial port1 function
Any instruction causes a write to SBUF1 will start the transmission of serial port1. As the REN1 is from
0 to 1, the serial port1 begins to receive a byte into SBUF1 in the frequency of the serial clock. REN1
could be cleared by software after receive function begins. The LSB is transmitted/ received first. The
I/O mode of serial clock pin is controlled by CLKIO. User has to take care the initial state of the serial
port pins.
C1
C2
C3
C4
REN1
P4.0
SEDG=1, rising latch
P4.0
SEDG=0, falling latch
1234 56 78
1234 56 78
SF1
P4.1
Data Input
NOTE: The serial clock frequency is fosc/2
Figure 6-6 Timing of the Serial port1 Input Function
- 60 -