DS89C440 Maxim, DS89C440 Datasheet - Page 10

• Manufacturer Part Number: DS89C440
• Description: The DS89C430 and DS89C450 offer the highest performance available in 8051-compatible microcontrollers
• Manufacturer: Maxim

Figure 4. 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
XLXL
D0
t
XHQX
DI
DI
D2
D0
D2
DS89C430/DS89C450 Ultra-High-Speed Flash Microcontrollers
D0
10 of 46
D3
t
XHDX
D3
1/(XTAL FREQ/12)
D4
D4
DI
D5
DI
D5
D6
D6
D6
D6
D7
D7
D7
D7
TRANSMIT
RECEIVE