DS89C420 Dallas Semiconducotr, DS89C420 Datasheet - Page 53

• Manufacturer Part Number: DS89C420
• Description: Ultra-High-Speed Microcontroller
• Manufacturer: Dallas Semiconducotr

Figure 15. Serial Port Timing
SERIAL PORT (SYNCHRONOUS MODE)
SM2 = 1
SERIAL PORT (SYNCHRONOUS MODE)
SM2 = 0
WRITE TO SCON
TO CLEAR RI
WRITE TO SBUF
RXD DATA OUT
TXD CLOCK
RXD DATA IN
TXD CLOCK
WRITE TO SBUF
RXD DATA OUT
WRITE TO SCON
TO CLEAR RI
TXD CLOCK
RXD DATA IN
TXD CLOCK
PSEN
TXD CLOCK
ALE
TI
R1
PSEN
ALE
TI
R1
TDX CLOCK = XTAL FREQ/4
TDX CLOCK = XTAL FREQ/12
t
XHDV
t
QVXH
D0
t
D0
XLXL
t
XHQX
DI
DI
D2
D0
D2
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D0
D3
t
XHDX
D3
1/(XTAL FREQ/12)
D4
D4
DI
D5
DI
D5
D6
D6
D6
D6
D7
D7
D7
D7
TRANSMIT
RECEIVE