ATA5771_09 Datasheet, PDF (122/287 Pages) ATMEL Corporation – Microcontroller with UHF ASK/FSK Transmitter

ATtiny24/44/84
• Port B, Bit 3 – RESET/dW/PCINT11
RESET: External Reset input is active low and enabled by unprogramming (“1”) the RSTDISBL
Fuse. Pullup is activated and output driver and digital input are deactivated when the pin is used
as the RESET pin.
dW: When the debugWIRE Enable (DWEN) Fuse is programmed and Lock bits are unpro-
grammed, the debugWIRE system within the target device is activated. The RESET port pin is
configured as a wire-AND (open-drain) bi-directional I/O pin with pull-up enabled and becomes
the communication gateway between target and emulator.
PCINT11: Pin Change Interrupt source 11. The PB3 pin can serve as an external interrupt
source for pin change interrupt 1.
Table 12-8 on page 69 and Table 12-9 on page 70 relate the alternate functions of Port B to the
overriding signals shown in Figure 12-5 on page 62.
Table 12-8. Overriding Signals for Alternate Functions in PB3..PB2
Signal
Name
PUOE
PB3/RESET/dW/
PCINT11
RSTDISBL ⁽¹⁾+ DEBUGWIRE_ENABLE ⁽²⁾
PB2/INT0/OC0A/CKOUT/PCINT10
CKOUT
PUOV
DDOE
DDOV
PVOE
1
RSTDISBL⁽¹⁾ + DEBUGWIRE_ENABLE⁽²⁾
DEBUGWIRE_ENABLE⁽²⁾ • debugWire
Transmit
RSTDISBL⁽¹⁾ + DEBUGWIRE_ENABLE⁽²⁾
0
CKOUT
1'b1
CKOUT + OC0A enable
PVOV 0
CKOUT • System Clock + CKOUT • OC0A
PTOE
DIEOE
DIEOV
0
RSTDISBL⁽¹⁾ + DEBUGWIRE_ENABLE⁽²⁾ +
PCINT11 • PCIE1
DEBUGWIRE_ENABLE⁽²⁾ + (RSTDISBL⁽¹⁾ •
PCINT11 • PCIE1)
0
PCINT10 • PCIE1 + INT0
PCINT10 • PCIE1 + INT0
DI
dW/PCINT11 Input
INT0/PCINT10 Input
AIO
1.
RSTDISBL is 1 when the Fuse is “0” (Programmed).
2.
DebugWIRE is enabled wheb DWEN Fuse is programmed and Lock bits are unprogrammed.
69
7701C–AVR–12/08