SH7046 Datasheet, PDF (496/611 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7046 Series

Section 17 I/O Ports
17.2.2 Port B Data Register (PBDR)
The port B data register (PBDR) is a 16-bit readable/writable register that stores port B data. Bits
PB5DR to PB2DR correspond to pins PB5 to PB2 (multiplexed functions omitted here).
When a pin functions is a general output, if a value is written to PBDR, that value is output
directly from the pin, and if PBDR is read, the register value is returned directly regardless of the
pin state.
When a pin functions is a general input, if PBDR is read, the pin state, not the register value, is
returned directly. If a value is written to PBDR, although that value is written into PBDR, it does
not affect the pin state. Table 17.2 summarizes port B data register read/write operations.
Initial
Bit
Bit Name Value R/W
15 to 
6
All 0 R
5
PB5DR
4
PB4DR
3
PB3DR
2
PB2DR
1, 0 
0
R/W
0
R/W
0
R/W
0
R/W
All 0 R
Description
Reserved
These bits are always read as 0, and should only be
written with 0.
See table 17.2
Reserved
These bits are always read as 0, and should only be
written with 0.
Table 17.2 Port B Data Register (PBDR) Read/Write Operations
Bits 5 to 2:
PBIOR
0
1
Pin Function
General input
Other than
general input
General output
Other than
general output
Read
Pin state
Pin state
PBDR value
PBDR value
Write
Can write to PBDR, but it has no effect on pin state
Can write to PBDR, but it has no effect on pin state
Value written is output from pin
Can write to PBDR, but it has no effect on pin state
Rev. 4.00 Dec 05, 2005 page 452 of 564
REJ09B0270-0400