AT89C51RB2-3CSUL Atmel, AT89C51RB2-3CSUL Datasheet - Page 72
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AT89C51RB2-3CSUL
Manufacturer Part Number
AT89C51RB2-3CSUL
Description
MCU 8051 16K FLASH 3V 44-PLCC
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51RB2-RLTIL.pdf
(127 pages)
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
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Figure 28. Data Transmission Format (CPHA = 0)
Figure 29. Data Transmission Format (CPHA = 1)
Figure 30. CPHA/SS Timing
72
AT89C51RB2/RC2
MOSI (from Master)
SCK Cycle Number
MISO (from Slave)
MOSI (from Master)
SCK (CPOL = 0)
SCK (CPOL = 1)
MISO (from Slave)
SCK Cycle Number
SPEN (Internal)
SCK (CPOL = 0)
SCK (CPOL = 1)
Capture Point
SPEN (Internal)
SS (to Slave)
Capture Point
SS (to Slave)
MISO/MOSI
(CPHA = 0)
(CPHA = 1)
Master SS
Slave SS
Slave SS
As shown in Figure 28, the first SCK edge is the MSB capture strobe. Therefore, the
Slave must begin driving its data before the first SCK edge, and a falling edge on the SS
pin is used to start the transmission. The SS pin must be toggled high and then low
between each Byte transmitted (Figure 30).
Figure 29 shows an SPI transmission in which CPHA is ’1’. In this case, the Master
begins driving its MOSI pin on the first SCK edge. Therefore, the Slave uses the first
SCK edge as a start transmission signal. The SS pin can remain low between transmis-
sions (Figure 30). This format may be preffered in systems having only one Master and
only one Slave driving the MISO data line.
MSB
MSB
MSB
1
MSB
1
2
bit6
bit6
2
bit6
bit6
Byte 1
3
bit5
bit5
3
bit5
bit5
bit4
bit4
4
bit4
4
bit4
Byte 2
bit3
5
bit3
bit3
5
bit3
6
bit2
bit2
6
bit2
bit2
Byte 3
7
bit1
bit1
7
bit1
bit1
LSB
8
LSB
LSB
8
LSB
4180E–8051–10/06