AT89C51RB2-3CSUL Atmel, AT89C51RB2-3CSUL Datasheet - Page 76

• Manufacturer Part Number: AT89C51RB2-3CSUL
• Description: MCU 8051 16K FLASH 3V 44-PLCC
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51RB2-3CSUL

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1280 B
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Mounting Style: Through Hole
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• For Use With: AT89STK-11 - KIT STARTER FOR AT89C51RX2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

Serial Peripheral DATa Register
(SPDAT)
76
AT89C51RB2/RC2
Reset Value = 00X0 XXXXb
Not Bit addressable
The Serial Peripheral Data Register (Table 58) is a read/write buffer for the receive data
register. A write to SPDAT places data directly into the shift register. No transmit buffer is
available in this model.
A Read of the SPDAT returns the value located in the receive buffer and not the content
of the shift register.
Table 58. SPDAT Register
SPDAT - Serial Peripheral Data Register (0C5H)
Reset Value = Indeterminate
R7:R0: Receive data bits
SPCON, SPSTA and SPDAT registers may be read and written at any time while there
is no on-going exchange. However, special care should be taken when writing to them
while a transmission is on-going:
•
•
•
•
•
Number
Bit
Do not change SPR2, SPR1 and SPR0
Do not change CPHA and CPOL
Do not change MSTR
Clearing SPEN would immediately disable the peripheral
Writing to the SPDAT will cause an overflow.
R7
7
1
0
Mnemonic Description
Bit
R6
6
-
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
R5
5
R4
4
R3
3
R2
2
R1
1
4180E–8051–10/06
R0
0