AT89C51RE2-SLRUM Atmel, AT89C51RE2-SLRUM Datasheet - Page 149

• Manufacturer Part Number: AT89C51RE2-SLRUM
• Description: MCU 8051 128K FLASH 44-PLCC
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51RE2-SLRUM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 60MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 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: 8 KB
• Interface Type: UART, SPI
• Maximum Clock Frequency: 60 MHz
• Number Of Programmable I/os: 34
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89OCD-01
• For Use With: AT89STK-11 - KIT STARTER FOR AT89C51RX2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Serial Port
Interface (SPI)
Features
Signal Description
Master Output Slave
Input (MOSI)
Master Input Slave
Output (MISO)
SPI Serial Clock (SCK) This signal is used to synchronize the data transmission both in and out of the devices through
Slave Select (SS)
7663E–8051–10/08
The Serial Peripheral Interface Module (SPI) allows full-duplex, synchronous, serial communica-
tion between the MCU and peripheral devices, including other MCUs.
Features of the SPI Module include the following:
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•
•
•
•
Figure 56 shows a typical SPI bus configuration using one Master controller and many Slave
peripherals. The bus is made of three wires connecting all the devices.
Figure 56. SPI Master/Slaves Interconnection
The Master device selects the individual Slave devices by using four pins of a parallel port to
control the four SS pins of the Slave devices.
This 1-bit signal is directly connected between the Master Device and a Slave Device. The MOSI
line is used to transfer data in series from the Master to the Slave. Therefore, it is an output sig-
nal from the Master, and an input signal to a Slave. A Byte (8-bit word) is transmitted most
significant bit (MSB) first, least significant bit (LSB) last.
This 1-bit signal is directly connected between the Slave Device and a Master Device. The MISO
line is used to transfer data in series from the Slave to the Master. Therefore, it is an output sig-
nal from the Slave, and an input signal to the Master. A Byte (8-bit word) is transmitted most
significant bit (MSB) first, least significant bit (LSB) last.
their MOSI and MISO lines. It is driven by the Master for eight clock cycles which allows to
exchange one Byte on the serial lines.
Each Slave peripheral is selected by one Slave Select pin (SS). This signal must stay low for any
message for a Slave. It is obvious that only one Master (SS high level) can drive the network.
The Master may select each Slave device by software through port pins (Figure 57). To prevent
bus conflicts on the MISO line, only one slave should be selected at a time by the Master for a
transmission.
Full-duplex, three-wire synchronous transfers
Master or Slave operation
Six programmable Master clock rates in master mode
Serial clock with programmable polarity and phase
Master Mode fault error flag with MCU interrupt capability
Master
Slave 4
MISO
MOSI
SCK
SS
0
1
2
3
VDD
Slave 3
Slave 1
Slave 2
AT89C51RE2
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