Datasheet

Section 9 I/O Ports
Rev.6.00 Sep. 27, 2007 Page 433 of 1268
REJ09B0220-0600
9.13.3 Pin Functions
Port F pins also function as bus control signal input/output pins (AS, RD, HWR, LWR, LCAS
*
,
WAIT, BREQO, BREQ, and BACK) and the system clock (φ) output pin. The pin functions differ
between modes 4 to 6, and mode 7. Port F pin functions are shown in table 9.25.
Note: * The LCAS is not supported in the H8S/2321.
Table 9.25 Port F Pin Functions
Pin Selection Method and Pin Functions
PF
7
/φ The pin function is switched as shown below according to bit PF7DDR.
PF7DDR 0 1
Pin function PF
7
input pin φ output pin
PF
6
/AS The pin function is switched as shown below according to the operating mode,
bit PF6DDR, and bit ASOD in PFCR2.
Operating
Mode
Modes 4 to 6 Mode 7
ASOD 0 1 —
PF6DDR — 0 1 0 1
Pin function AS output
pin
PF
6
input
pin
PF
6
output
pin
PF
6
input
pin
PF
6
output
pin
PF
5
/RD The pin function is switched as shown below according to the operating mode
and bit PF5DDR.
Operating
Mode
Modes 4 to 6 Mode 7
PF5DDR — 0 1
Pin function RD output pin PF
5
input pin PF
5
output pin
PF
4
/HWR The pin function is switched as shown below according to the operating mode
and bit PF4DDR.
Operating
Mode
Modes 4 to 6 Mode 7
PF4DDR — 0 1
Pin function HWR output pin PF
4
input pin PF
4
output pin