Advertisement
10.12.3 Pin Functions
Port F pins also function as external interrupt input pins (IRQ2 and IRQ3), BUZZ output pin, A/D
trigger input pin (ADTRG), bus control signal input/output pins (AS, RD, HWR, LWR, LCAS,
WAIT, BREQO, BREQ, and BACK) and the system clock (ø) output pin. The pin functions differ
between modes 4 to 6, and mode 7. Port F pin functions are shown in table 10-21.
Table 10-21 Port F Pin Functions
Pin
PF7/ø
PF6/AS/LCAS
PF5/RD
PF4/HWR
Selection Method and Pin Functions
The pin function is switched as shown below according to bit PF7DDR.
PF7DDR
Pin function
The pin function is switched as shown below according to the combination of
the operating mode and bits RMTS2 to RMTS0, LCASS, BREQOE, WAITE,
ABW5 to ABW2, and PF2DDR.
Operating
Mode
LCASS
PF6DDR
AS output pin
Pin function
Note: * Restricted to RMTS2 to TMTS0=B'001 to B'011, DRAM space 16-bit
access in modes 4 to 6 only
The pin function is switched as shown below according to the operating mode
and bit PF5DDR.
Operating
Mode
PF5DDR
Pin function
The pin function is switched as shown below according to the operating mode
and bit PF4DDR.
Operating
Mode
PF4DDR
HWR output pin
Pin function
0
PF7 input pin
Modes 4 to 6
0
1*
—
—
LCAS
output pin
Modes 4 to 6
—
RD output pin
Modes 4 to 6
—
ø output pin
Mode 7
0
PF6 input pin PF6 output pin
Mode 7
0
PF5 input pin
Mode 7
0
PF4 input pin
1
—
1
1
PF5 output pin
1
PF4 output pin
395
Advertisement
