SH7108 Datasheet, PDF (472/560 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

Section 15 I/O Ports
15.4.2 Port E Data Registers H and L (PEDRH and PEDRL)
PEDRH and PEDRL are 16-bit readable/writable registers that store port E data. Bits PE21DR to
PE0DR correspond to pins PE21 to PE0 (multiplexed functions omitted here).
When a pin functions is a general output, if a value is written to PEDRH or PEDRL, that value is
output directly from the pin, and if PEDRH or PEDRL is read, the register value is returned
directly regardless of the pin state.
When a pin functions is a general input, if PEDRH or PEDRL is read, the pin state, not the register
value, is returned directly. If a value is written to PEDRH or PEDRL, although that value is
written into PEDRH or PEDRL it does not affect the pin state. Table 15.4 summarizes port E data
register read/write operations.
• PEDRH
Bit
Bit Name Initial Value R/W
15 to 6 —
All 0
R
5
PE21DR 0
R/W
4
PE20DR 0
R/W
3
PE19DR 0
R/W
2
PE18DR 0
R/W
1
PE17DR 0
R/W
0
PE16DR 0
R/W
Description
Reserved
These bits are always read as 0. The write value
should always be 0.
See table 15.4.
Rev.1.00 Sep. 18, 2008 Page 438 of 522
REJ09B0069-0100