MC68HC908JW32_09 Datasheet, PDF (170/232 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Input/Output (I/O) Ports
Port
E
Table 13-1. Port Control Register Bits Summary (Continued)
Bit
DDR
2
DDRE2
3
DDRE3
4
DDRE4
5
DDRE5
6
DDRE6
7
DDRE7
Module
USB
PULLUP
PS2CLK
USB
PULLUP
IRQ
Module Control
Register
USBCR ($51)
POCR2 ($1B)
PS2CSR ($19)
USBCR ($51)
POCR2 ($1B)
IOCR ($1C)
Control Bit
USBEN
PTE2P
PS2EN
USBEN
PTE3P
PTE3IE
SPI
SPCR ($4C)
SPE
Pin
PTE2/D+
PTE3/D–
PTE4/SPSCK
PTE5/MOSI
PTE6/MISO
PTE7/SS
13.2 Port A
Port A is an 8-bit general-purpose bidirectional I/O port with software configurable pullups, and it shares
its pins with the keyboard interrupt module (KBI).
13.2.1 Port A Data Register
The port A data register contains a data latch for each of the eight port A pins.
Address:
Read:
Write:
Reset:
Alternative
Function:
Additional
Function:
$0000
Bit 7
PTA7
KBA7
Optional
pullup
6
5
4
3
2
PTA6
PTA5
PTA4
PTA3
PTA2
Unaffected by reset
KBA6
KBA5
KBA4
KBA3
KBA2
Optional Optional Optional Optional Optional
pullup
pullup
pullup
pullup
pullup
Figure 13-2. Port A Data Register (PTA)
1
PTA1
KBA1
Optional
pullup
Bit 0
PTA0
KBA0
Optional
pullup
PTA[7:0] — Port A Data Bits
These read/write bits are software programmable. Data direction of each port A pin is under the control
of the corresponding bit in data direction register A. Reset has no effect on port A data.
KBA7–KBA0 — Keyboard Interrupts
The keyboard interrupt enable bits, KBA7–KBA0, in the keyboard interrupt enable register (KBIER),
enable the port A pins as external interrupt pins and the internal pullup of the corresponding pin. (See
Chapter 15 Keyboard Interrupt Module (KBI).)
MC68HC908JW32 Data Sheet, Rev. 6
170
Freescale Semiconductor