MC68HC908QB8 Datasheet, PDF (22/236 Pages) Freescale Semiconductor, Inc – To provide the most up-to-date information, the revision of our documents

General Description
Pin
Name
PTB4
PTB5
PTB6
PTB7
Table 1-2. Pin Functions (Continued)
PTB4 — General-purpose I/O port
RxD — ESCI receive data I/O
AD8 — A/D channel 8 input
PTB5 — General-purpose I/O port
TxD — ESCI transmit data I/O
AD9 — A/D channel 9 input
PTB6 — General-purpose I/O port
TCH2 — Timer channel 2 I/O
PTB7 — General-purpose I/O port
TCH3 — Timer channel 3 I/O
Description
Input/Output
Input/Output
Input/Output
Input
Input/Output
Output
Input
Input/Output
Input/Output
Input/Output
Input/Output
1.6 Pin Function Priority
Table 1-3 is meant to resolve the priority if multiple functions are enabled on a single pin.
NOTE
Upon reset all pins come up as input ports regardless of the priority table.
Table 1-3. Function Priority in Shared Pins
Pin Name
PTA0⁽¹⁾
PTA1⁽¹⁾
PTA2
PTA3
PTA4⁽¹⁾
PTA5⁽¹⁾
PTB0⁽¹⁾
PTB1⁽¹⁾
PTB2⁽¹⁾
PTB3⁽¹⁾
PTB4⁽¹⁾
PTB5⁽¹⁾
PTB6
PTB7
Highest-to-Lowest Priority Sequence
AD0 → TCH0 → KBI0 → PTA0
AD1 → TCH1 → KBI1 → PTA1
IRQ → TCLK → KBI2 → PTA2
RST → KBI3 → PTA3
OSC2 → AD2 → KBI4 → PTA4
OSC1 → AD3 → KBI5 → PTA5
AD4 → SPSCK → PTB0
AD5 → MOSI → PTB1
AD6 → MISO → PTB2
AD7 → SS → PTB3
AD8 → RxD → PTB4
AD9 → TxD → PTB5
TCH2 → PTB6
TCH3 → PTB7
1. When a pin is to be used as an ADC pin, the I/O port function should be left as
an input and all other shared modules should be disabled. The ADC does not
override additional modules using the pin.
MC68HC908QB8 Data Sheet, Rev. 1
22
Freescale Semiconductor