
MC68HC16V1
MOTOROLA
MC68HC16V1TS/D
55
When read, the port F pin data register reflects the current state of the port F pins, regardless of whether
the pins are configured as inputs or outputs. Writes have no effect.
Port F data direction register bits control the direction of the port F pin drivers when the pins are config-
ured as I/O pins. When any bit in this register is set to one, the corresponding pin is configured as an
output. When any bit in this register is cleared to zero, the corresponding pin is configured as an input.
Reset clears all bits to zero.
Each of the eight fields in this register controls the function of a port F pin. Field encodings 01 and 10
configure the pin as a rising or falling edge-detect I/O pin controlled by the port F data and data direction
registers.
When a field in this register is set to 11, the corresponding pin is configured as a level-sensitive interrupt
request input for pins IRQ7/PF7, IRQ2/PF2, and IRQX/PF1, and as digital I/O on ALE/PF0.
When a field in this register is programmed to 00, the corresponding pin is configured as an edge-sen-
sitive interrupt request input for pins IRQ7/PF7, IRQ2/PF2, and IRQX/PF1, and as digital I/O on pin
ALE/PF0.
The IRQX/BERR signal operates as bus error when IRQXL[2:0] = %000 in the port F interrupt level reg-
ister (PFLVR), regardless of the setting of the port F pin assignment register PFPA1 field.
Refer to Table 36 for port F pin assignments. Table 37 displays port F pin assignment register field en-
codings.
PORTFP — Port F Pin Data Register
$YFFA33
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NOT USED
PFP7
RESERVED
PFP2
PFP1
PFP0
RESET:
CURRENT STATE OF CORRESPONDING PINS
DDRF — Port F Data Direction Register
$YFFA35
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NOT USED
DDF7
RESERVED
DDF2
DDF1
DDF0
RESET:
0
PFPAR — Port F Pin Assignment Register
$YFFA36
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PFPA7
RESERVED
PFPA2
PFPA1
PFPA0
RESET
1
*
*0 if multiplexed SLIM configuration is selected, otherwise 1