at89c5131 ATMEL Corporation, at89c5131 Datasheet - Page 8

• Manufacturer Part Number: at89c5131
• Description: 8-bit Flash Microcontroller With Full Speed Usb Device At89c5131
• Manufacturer: ATMEL Corporation

8
AT89C5131
Table 4. Timer 0, Timer 1 and Timer 2 Signal Description (Continued)
Table 5. LED Signal Description
Table 6. TWI Signal Description
Table 7. SPI Signal Description
LED[3:0]
Signal
Signal
Name
Name
Signal
Signal
Name
Name
T2EX
MISO
MOSI
SCK
SCL
SDA
SS
T0
T1
T2
Type
Type
Type
Type
I/O
I/O
I/O
I/O
O
I/O
I/O
I
I
I
I
O
Description
Timer Counter 0 External Clock Input
When Timer 0 operates as a counter, a falling edge on the T0 pin
increments the count.
Timer/Counter 1 External Clock Input
When Timer 1 operates as a counter, a falling edge on the T1 pin
increments the count.
Timer/Counter 2 External Clock Input
Timer/Counter 2 Clock Output
Timer/Counter 2 Reload/Capture/Direction Control Input
Description
SS: SPI Slave Select
MISO: SPI Master Input Slave Output line
When SPI is in master mode, MISO receives data from the slave
peripheral. When SPI is in slave mode, MISO outputs data to the master
controller.
SCK: SPI Serial Clock
SCK outputs clock to the slave peripheral or receive clock from the master
MOSI: SPI Master Output Slave Input line
When SPI is in master mode, MOSI outputs data to the slave peripheral.
When SPI is in slave mode, MOSI receives data from the master controller
Description
Direct Drive LED Output
These pins can be directly connected to the Cathode of standard LEDs
without external current limiting resistors. The typical current of each
output can be programmed by software to 2, 6 or 10 mA. Several outputs
can be connected together to get higher drive capabilities.
Description
SCL: TWI Serial Clock
SCL output the serial clock to slave peripherals.
SCL input the serial clock from master.
SDA: TWI Serial Data
SCL is the bidirectional TWI data line.
4136C–USB–04/05
Alternate
Function
Alternate
Function
Alternate
Function
Alternate
Function
P3.4
P3.5
P1.0
P1.1
P3.3
P3.5
P3.6
P3.7
P4.0
P4.1
P1.1
P1.5
P1.6
P1.7