Rainbow Electronics ATmega8515L - Manual (Page 65)

65
ATmega8515(L)
2512A–AVR–04/02
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.
• MOSI – Port B, Bit 5
MOSI: SPI Master Data output, Slave Data input for SPI channel. When the SPI is
enabled as a Slave, this pin is configured as an input regardless of the setting of DDB5.
When the SPI is enabled as a Master, the data direction of this pin is controlled by
DDB5. When the pin is forced by the SPI to be an input, the pull-up can still be con-
trolled by the PORTB5 bit.
• SS – Port B, Bit 4
SS: Slave Select input. When the SPI is enabled as a Slave, this pin is configured as an
input regardless of the setting of DDB4. As a Slave, the SPI is activated when this pin is
driven low. When the SPI is enabled as a Master, the data direction of this pin is con-
trolled by DDB4. When the pin is forced by the SPI to be an input, the pull-up can still be
controlled by the PORTB4 bit.
• AIN1 – Port B, Bit 3
AIN1, Analog Comparator Negative input. Configure the port pin as input with the inter-
nal pull-up switched off to avoid the digital port function from interfering with the function
of the Analog Comparator.
• AIN0 – Port B, Bit 2
AIN0, Analog Comparator Positive input. Configure the port pin as input with the internal
pull-up switched off to avoid the digital port function from interfering with the function of
the Analog Comparator.
• T1 – Port B, Bit 1
T1, Timer/Counter1 Counter Source.
• T0/OC0 – Port B, Bit 0
T0, Timer/Counter0 Counter Source.
OC0, Output Compare Match output: The PB0 pin can serve as an external output for
the Timer/Counter0 Compare Match. The PB0 pin has to be configured as an output
(DDB0 set (one)) to serve this function. The OC0 pin is also the output pin for the PWM
mode timer function.
Table 31 relate the alternate functions of Port B to the overriding signals shown in Figure
32 on page 61. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute the MISO signal,
while MOSI is divided into SPI MSTR OUTPUT and SPI SLAVE INPUT.