MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 265

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

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.
PTH[1:0] — Port H Data Bits
KBD[4:3] — Keyboard Wake-up pins
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.
DDRH[1:0] — Data Direction Register H Bits
Freescale Semiconductor
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].
The keyboard interrupt enable bits, KBIE[4:3], in the keyboard interrupt control register, enable the port
H pins as external interrupt pins (See
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
Alternative
Function:
Address:
Address:
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.
Reset:
Reset:
Read:
Read:
Write:
Write:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
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Bit 7
Bit 7
R
R
R
R
0
0
0
Figure 22-24. Data Direction Register H (DDRH)
Figure 22-23. Port H Data Register (PTH)
= Reserved
= Reserved
R
R
6
0
6
0
0
Chapter 24 Keyboard Module
R
R
5
0
5
0
0
NOTE
Unaffected by Reset
R
R
4
0
4
0
0
R
R
3
0
3
0
0
R
R
2
0
2
0
0
(KBI)).
DDRH1
PTH1
KBD4
1
1
0
DDRH0
PTH0
KBD3
Bit 0
Bit 0
0
Port H
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