Datasheet

81
7734Q–AVR–02/12
AT90PWM81/161
ACMP1M: Analog Comparator 1 Negative 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 Ana-
log Comparator.
PCSINr: PSCR Digital Input.
• XTAL1/PSCIN2/ACMP1_OUT – Bit 1
XTAL1: Chip clock Oscillator pin 1. Used for all chip clock sources except internal calibrated RC
Oscillator. When used as a clock pin, the pin can not be used as an I/O pin.
PCSIN2: PSC 2 Digital Input.
ACMP1_OUT: Analog Comparator 1 Output.
• RESET
/OCD/INT2 – Bit 0
RESET
: Reset pin: When the RSTDISBL Fuse is programmed, this pin functions as a normal I/O
pin, and the part will have to rely on Power-on Reset and Brown-out Reset as its reset sources.
When the RSTDISBL Fuse is unprogrammed, the reset circuitry is connected to the pin, and the
pin can not be used as an I/O pin.
If PE0 is used as a reset pin, DDE0, PORTE0 and PINE0 will all read 0.
INT2: External Interrupt source 2. This pin can serve as an External Interrupt source to the MCU.
Table 9-10 relates the alternate functions of Port E to the overriding signals shown in Figure 9-5
on page 73.
9.4 Register Description for I/O-Ports
9.4.1 PORTB - Port B Data Register
Table 9-10. Overriding signals for alternate functions in PE2..PE0.
Signal name PE3/AREF/ADC6
PE2/XTAL2/ACM
P1M/PSCINr
PE1/XTAL1/PSCI
N2/ ACMP1_OUT
PE0/RESET
/OCD/
INT2
PUOE0000
PUOV0000
DDOE 0 0 AC1EN 0
DDOV 0 0 1 0
PVOE 0 0 AC1EN 0
PVOV 0 0 ACMP1_OUT 0
DIEOE 0 ACMP1MD 0 In2en
DIEOV000In2en
DI - PSCINr PSCIN2 INT2
AIO ADC6 ACMP1M - -
Bit 76543210
PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 PORTB
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000