MC908AZ60ACFUER Datasheet, PDF (265/414 Pages) Freescale Semiconductor, Inc – To provide the most up-to-date information, the revision of our documents on the World Wide Web will be the most current. Your printed copy may be an earlier revision. To verify you have the latest information available, refer to:

Port H
22.9 Port H
Port H is a 2-bit special function port that shares all of its pins with the keyboard interrupt module (KBD).
Note that Port H is only available on 64-pin package options.
22.9.1 Port H Data Register
The port H data register contains a data latch for each of the two port H pins.
Address:
Read:
Write:
Reset:
Alternative
Function:
$000B
Bit 7
0
R
R
6
5
4
3
2
0
0
0
0
0
R
R
R
R
R
Unaffected by Reset
= Reserved
Figure 22-23. Port H Data Register (PTH)
1
PTH1
KBD4
Bit 0
PTH0
KBD3
PTH[1:0] — Port H Data Bits
These read/write bits are software programmable. Data direction of each port H pin is under the control
of the corresponding bit in data direction register H. Reset has no effect on PTH[1:0].
KBD[4:3] — Keyboard Wake-up pins
The keyboard interrupt enable bits, KBIE[4:3], in the keyboard interrupt control register, enable the port
H pins as external interrupt pins (See Chapter 24 Keyboard Module (KBI)).
22.9.2 Data Direction Register H
Data direction register H determines whether each port H pin is an input or an output. Writing a logic 1 to
a DDRH bit enables the output buffer for the corresponding port H pin; a logic 0 disables the output buffer.
Address:
Read:
Write:
Reset:
$000F
Bit 7
6
5
4
3
2
1
0
0
0
0
0
0
DDRH1
R
R
R
R
R
R
0
0
0
0
0
0
0
R
= Reserved
Figure 22-24. Data Direction Register H (DDRH)
Bit 0
DDRH0
0
DDRH[1:0] — Data Direction Register H Bits
These read/write bits control port H data direction. Reset clears DDRG[1:0], configuring all port H pins
as inputs.
1 = Corresponding port H pin configured as output
0 = Corresponding port H pin configured as input
NOTE
Avoid glitches on port H pins by writing to the port H data register before
changing data direction register H bits from 0 to 1.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor
265