Hitachi H8S/2670, Reference Manual

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5.14.2 Register Configuration
Table 5.29 shows the port E register configuration.
Table 5.29 Port E Registers
Name Abbreviation R/W Initial Value Address *
Port E data direction register PEDDR W H'00 H'FE2D
Port E data register PEDR R/W H'00 H'FF6D
Port E register PORTE R Undefined H'FF5D
Port E MOS pull-up control register PEPCR R/W H'00 H'FE3A
Note:
*
Lower 16 bits of the address.
Port E Data Direction Register (PEDDR)
Bit 7 6 5 4 3 2 1 0
PE7DDR PE6DDR PE5DDR PE4DDR PE3DDR PE2DDR PE1DDR PE0DDR
Initial value 0 0 0 0 0 0 0 0
Read/Write W W W W W W W W
PEDDR is an 8-bit write-only register, the individual bits of which specify input or output for the
pins of port E. PEDDR cannot be read; if it is, an undefined value will be read.
PEDDR is initialized to H'00 by a reset and in hardware standby mode. It retains its prior state in
software standby mode.
•
Modes 1, 2, 4, 5, and 6
When 8-bit bus mode is selected, port E functions as an I/O port. The pin states can be changed
with PEDDR. When 16-bit bus mode is selected, the input/output direction specification by
PEDDR is ignored and port E is designated for data input/output.
For details of 8-bit and 16-bit bus modes, see section 4, Bus Controller.
•
Mode 7 (when bit EXPE is set to 1 in SYSCR)
When 8-bit bus mode is selected, port E functions as an I/O port. Setting a PEDDR bit to 1
makes the corresponding port E pin an output port, while clearing the bit to 0 makes the pin an
input port. When 16-bit bus mode is selected, the input/output direction specification by
PEDDR is ignored and port E is designated for data input/output.
•
Mode 7 (when bit EXPE is cleared to 0 in SYSCR)
Port E is an I/O port, and its pin functions can be switched with PEDDR.