Rainbow Electronics ATmega64L - Manual (Page 55)

55
ATmega16(L)
2466B–09/01
Alternate Functions of Port B The Port B pins with alternate functions are shown in Table 25.
The alternate pin configuration is as follows:
• SCK - Port B, Bit 7
SCK: Master clock output, slave clock input pin for SPI channel. When the SPI is
enabled as a slave, this pin is configured as an input regardless of the setting of DDB7.
When the SPI is enabled as a master, the data direction of this pin is controlled by
DDB7. When the pin is forced by the SPI to be an input, the pull-up can still be con-
trolled by the PORTB7 bit.
• MISO - Port B, Bit 6
MISO: Master data input, slave data output pin for SPI channel. When the SPI is
enabled as a master, this pin is configured as an input regardless of the setting of
DDB6. When the SPI is enabled as a slave, the data direction of this pin is controlled by
DDB6. When the pin is forced by the SPI to be an input, the pull-up can still be con-
trolled by the PORTB6 bit.
Table 24. Overriding Signals for Alternate Functions in PA3..PA0
Signal Name PA3/ADC3 PA2/ADC2 PA1/ADC1 PA0/ADC0
PUOE 0 0 0 0
PUOV 0 0 0 0
DDOE 0 0 0 0
DDOV 0 0 0 0
PVOE 0 0 0 0
PVOV 0 0 0 0
DIEOE 0 0 0 0
DIEOV 0 0 0 0
DI – – – –
AIO ADC3 INPUT ADC2 INPUT ADC1 INPUT ADC0 INPUT
Table 25. Port B Pins Alternate Functions
Port Pin Alternate Functions
PB7 SCK (SPI Bus Serial Clock)
PB6 MISO (SPI Bus Master Input/Slave Output)
PB5 MOSI (SPI Bus Master Output/Slave Input)
PB4 SS (SPI Slave Select Input)
PB3
AIN1 (Analog Comparator Negative Input)
OC0 (Timer/Counter0 Output Compare Match Output)
PB2
AIN0 (Analog Comparator Positive Input)
INT2 (External Interrupt 2 Input)
PB1 T1 (Timer/Counter 1 External Counter Input)
PB0
T0 (Timer/Counter 0 External Counter Input)
XCK (USART External Clock Input/Output)