MC68HC908AB32 Datasheet, PDF (323/392 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Input/Output (I/O) Ports
17.6 Port D
Port D is an 8-bit special function port that shares two of its pins with the
timer interface module (see Section 11. Timer Interface Module A
(TIMA) and Section 12. Timer Interface Module B (TIMB)). Each
port D pin has 15mA current drive (sink) and programmable pullup.
17.6.1 Port D Data Register (PTD)
The port D data register contains a data latch for each of the eight port D
pins.
Address: $0003
Read:
Write:
Bit 7
PTD7
6
PTD6
5
PTD5
4
PTD4
3
PTD3
2
PTD2
1
PTD1
Bit 0
PTD0
Reset:
Unaffected by reset
Alternative Function:
TACLK
TBCLK
Additional Functions: 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink 15mA sink
Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup Input pullup
Figure 17-11. Port D Data Register (PTD)
PTD[7:0] — Port D Data Bits
These read/write bits are software programmable. Data direction of
each port D pin is under the control of the corresponding bit in data
direction register D. Reset has no effect on port D data.
TACLK — Timer A Clock Input
The PTD6 pin becomes TACLK, the timer A (TIMA) external clock
input when the TIMA prescaler select bits, PS[2:0] = 111. See
Section 11. Timer Interface Module A (TIMA).
TBCLK — Timer B Clock Input
The PTD4 pin becomes TBCLK, the timer B (TIMB) external clock
input when the TIMB prescaler select bits, PS[2:0] = 111. See
Section 12. Timer Interface Module B (TIMB).
MC68HC908AB32 — Rev. 1.1
Freescale Semiconductor
Input/Output (I/O) Ports
Technical Data
323