MC68HC11PH8 Datasheet, PDF (87/264 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

4.8
Port H
Port H is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port H pins are shared with modulus timer and PWM functions, as shown in the
following table. Each port H pin configured as an input can be used as a keyboard interrupt, if
enabled (See Section 4.8.3).
Pin
Alternate
function
PH0
PW1

PH1
PW2


4
PH2
PW3


PH3
PW4


See Section 8 for
PH4
Ñ
 more information.

PH5
Ñ


PH6
Modulus timer C clock input


PH7 Modulus timer B clock input ^
On reset the pins are configured as general purpose high-impedance inputs with selectable
internal pull-ups (see Section 4.9).
4.8.1 PORTH — Port H data register
Port H data (PORTH)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$007C PH7 PH6 PH5 PH4 PH3 PH2 PH1 PH0 undeÞned
This is a read/write register and is not affected by reset. The bits may be read and written at any
time, but when one of the pins PH[3:0] is allocated to its alternate function of PWM channel, a write
to the corresponding register bit has no affect on the pin state.
4.8.2 DDRH — Data direction register for port H
Data direction H (DDRH)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$007D DDH7 DDH6 DDH5 DDH4 DDH3 DDH2 DDH1 DDH0 0000 0000
DDH[7:0] — Data direction for port H
1 (set) – The corresponding pin is configured as an output.
0 (clear) – The corresponding pin is configured as an input.
MC68HC11PH8
PARALLEL INPUT/OUTPUT
TPG
MOTOROLA
4-9