Datasheet

Pin Functions
MC68HC908QB8 Data Sheet, Rev. 3
Freescale Semiconductor 21
Table 1-2. Pin Functions
Pin
Name
Description Input/Output
V
DD
Power supply Power
V
SS
Power supply ground Power
PTA0
PTA0 — General purpose I/O port Input/Output
TCH0 — Timer Channel 0 I/O Input/Output
AD0 — A/D channel 0 input Input
KBI0 — Keyboard interrupt input 0 Input
PTA1
PTA1 — General purpose I/O port Input/Output
TCH1 — Timer Channel 1 I/O Input/Output
AD1 — A/D channel 1 input Input
KBI1 — Keyboard interrupt input 1 Input
PTA2
PTA2 — General purpose input-only port Input
IRQ
— External interrupt with programmable pullup and Schmitt trigger input Input
KBI2 — Keyboard interrupt input 2 Input
TCLK — Timer clock input Input
PTA3
PTA3 — General purpose I/O port Input/Output
RST
— Reset input, active low with internal pullup and Schmitt trigger Input
KBI3 — Keyboard interrupt input 3 Input
PTA4
PTA4 — General purpose I/O port Input/Output
OSC2 —XTAL oscillator output (XTAL option only)
RC or internal oscillator output (OSC2EN = 1 in PTAPUE register)
Output
Output
AD2 — A/D channel 2 input Input
KBI4 — Keyboard interrupt input 4 Input
PTA5
PTA5 — General purpose I/O port Input/Output
OSC1 — XTAL, RC, or external oscillator input Input
AD3 — A/D channel 3 input Input
KBI5 — Keyboard interrupt input 5 Input
PTB0
PTB0 — General-purpose I/O port Input/Output
SPSCK — SPI serial clock Input/Output
AD4 — A/D channel 4 input Input
PTB1
PTB1 — General-purpose I/O port Input/Output
MOSI — SPI Master out Slave in Input/Output
AD5 — A/D channel 5 input Input
PTB2
PTB2 — General-purpose I/O port Input/Output
MISO — SPI Master in Slave out Input/Output
AD6 — A/D channel 6 input Input
PTB3
PTB3 — General-purpose I/O port Input/Output
SS
— SPI slave select Input
AD7 — A/D channel 7 input Input
— Continued on next page