HD6473032F Datasheet, PDF (167/572 Pages) Hitachi Semiconductor – Hitachi Microcomputer

Bits 7 to 5, 3 and 1 are reserved. Bits 7 and 6 cannot be modified and always read 1. Bits 5, 3, and 1
can be written and read, but they cannot be used for port input or output. If bit 5, 3, or 1 in P9DDR
is read while its value is 1, the corresponding bit in P9DR is read directly. If bit 5, 3, or 1 in P9DDR
is read while its value is 0, it always reads 1.
P9DR is initialized to H'C0 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
7.9.3 Pin Functions
The port 9 pins are also used for SCI input and output (TxD, RxD, SCK), and for IRQ₄ input. Table
7-14 describes the selection of pin functions.
Table 7-14 Port 9 Pin Functions
Pin
P9₄/SCK/IRQ₄
Pin Functions and Selection Method
Bit C/A in SMR of SCI, bits CKE0 and CKE1 in SCR of SCI, and bit P9₄DDR
select the pin function as follows
P9₂/RxD
P9₀/TxD
CKE1
C/A
CKE0
P9₄DDR
Pin function
0
0
1
0
1
—
0
1
—
—
P9₄ P9₄ SCK output SCK output
input output
IRQ₄ input
1
—
—
—
SCK input
Bit RE in SCR of SCI and bit P9₂DDR select the pin function as follows
RE
P9₂DDR
Pin function
0
0
1
P9₂ input P9₂ output
1
—
RxD input
Bit TE in SCR of SCI and bit P9₀DDR select the pin function as follows
TE
P9₀DDR
Pin function
0
0
1
P9₀ input P9₀ output
1
—
TxD output
152