SH7055S Datasheet, PDF (749/1002 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

21.4.2 Port C Data Register (PCDR)
Bit: 15
14
13
12
11
10
9
8
—
—
—
—
—
—
—
—
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 7
6
5
4
3
2
1
0
—
—
—
PC4 PC3 PC2 PC1 PC0
DR
DR
DR
DR
DR
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R/W R/W R/W R/W R/W
The port C data register (PCDR) is a 16-bit readable/writable register that stores port C data. Bits
PC4DR to PC0DR correspond to pins PC4/IRQ0 to PC0/TxD1.
When a pin functions as a general output, if a value is written to PCDR, that value is output
directly from the pin, and if PCDR is read, the register value is returned directly regardless of the
pin state.
When a pin functions as a general input, if PCDR is read the pin state, not the register value, is
returned directly. If a value is written to PCDR, although that value is written into PCDR it does
not affect the pin state. Table 21.6 summarizes port C data register read/write operations.
PCDR is initialized to H'0000 by a power-on reset (excluding a WDT power-on reset), and in
hardware standby mode. It is not initialized in software standby mode or sleep mode.
• Bits 15 to 5—Reserved: These bits always read 0. The write value should always be 0.
Table 21.6 Port C Data Register (PCDR) Read/Write Operations
Bits 4 to 0:
PCIOR
Pin Function
0
General input
Other than
general input
1
General output
Other than
general output
Read
Pin state
Pin state
PCDR value
PCDR value
Write
Value is written to PCDR, but does not affect pin
state
Value is written to PCDR, but does not affect pin
state
Write value is output from pin
Value is written to PCDR, but does not affect pin
state
Rev.2.0, 07/03, page 711 of 960