SH7144 Datasheet, PDF (603/773 Pages) Renesas Technology Corp – Hitachi SuperH RISC engine

18.4.1 Register Descriptions
Port D is a 16-bit input/output port in the SH7144; a 32-bit input/output port in the SH7145. Port
D has the following registers. For details on register addresses and register states during each
processing, refer to section 25, List of Registers.
• Port D data register H (PDDRH)
• Port D data register L (PDDRL)
18.4.2 Port D Data Registers H and L (PDDRH and PDDRL)
The port D data registers H and L (PDDRH and PDDRL) are 16-bit readable/writable registers
that store port D data. Bits PD15DR to PD0DR correspond to pins PD15 to PD0 (multiplexed
functions omitted here) in the SH7144. Bits PD31DR to PD0DR correspond to pins PD31 to PD0
(multiplexed functions omitted here) in the SH7145.
When a pin functions is a general output, if a value is written to PDDRH or PDDRL, that value is
output directly from the pin, and if PDDRH or PDDRL is read, the register value is returned
directly regardless of the pin state.
When a pin functions is a general input, if PDDRH or PDDRL is read, the pin state, not the
register value, is returned directly. If a value is written to PDDRH or PDDRL, although that value
is written into PDDRH or PDDRL, it does not affect the pin state. Table 18.4 summarizes port D
data register L read/write operations.
Rev. 2.0, 09/02, page 563 of 732