AT89LP51 Atmel Corporation, AT89LP51 Datasheet - Page 72

• Manufacturer Part Number: AT89LP51
• Manufacturer: Atmel Corporation

Specifications of AT89LP51

• Flash (kbytes): 4 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 36
• Uart: 1
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: IAP
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 3
• Isp: SPI
• Watchdog: Yes

Figure 14-8. Serial Port Mode 3
72
SHIFT
TXD
TI
STOP BIT GEN
CLOCK
DATA
OVERFLOW
SMOD1
TIMER 1
BIT DETECTOR SAMPLE TIMES
TX
WRITE TO SBUF
AT89LP51/52
RCLK
TCLK
RI
÷2
SHIFT
“0”
START BIT
RXD
CLOCK
RX
“0”
“0”
SEND
“1”
OVERFLOW
TIMER 2
“1”
“1”
RXD
D0
WRITE
SAMPLE
SBUF
TO
TRANSITION
DETECTOR
INTERRUPT
START BIT
1-TO-0
÷16 RESET
D1
÷16
SERIAL
PORT
D2
D0
START
START
RX CLOCK
DETECTOR
÷16
CL
D
TB8
RX CLOCK
S
BIT
Q
D3
STOP BIT
D1
ZERO DETECTOR
RX CONTROL
TX CONTROL
READ
SBUF
RI
TI
INTERNAL BUS
LOAD
SBUF
D4
D2
SBUF
SHIFT
INTERNAL BUS
INPUT SHIFT REG.
SEND
SHIFT
1FFH
LOAD
SBUF
DATA
SBUF
D5
(9 BITS)
D3
D6
D4
SHIFT
D7
D5
TB8
D6
TXD
STOP BIT
D7
RB8
3709D–MICRO–12/11
STOP
BIT