HD6413008F RENESAS [Renesas Technology Corp], HD6413008F Datasheet - Page 198

• Manufacturer Part Number: HD6413008F
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7. I/O Ports
In the H8/3008, following a reset P8
P8DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
P8DDR is initialized to H'F0 by a reset and in hardware standby mode. In software standby mode
P8DDR retains its previous setting. Therefore, if a transition is made to software standby mode
while port 8 is functioning as an input/output port and a P8DDR bit is set to 1, the corresponding
pin maintains its output state.
Port 8 Data Register (P8DR): P8DR is an 8-bit readable/writable register that stores output data
for port 8. When port 8 functions as an output port, the value of this register is output. When a bit
in P8DDR is set to 1, if port 8 is read the value of the corresponding P8DR bit is returned. When a
bit in P8DDR is cleared to 0, if port 8 is read the corresponding pin logic level is read.
Bits 7 to 5 are reserved. They are fixed at 1, and cannot be modified.
P8DR is initialized to H'E0 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
Rev.4.00 Aug. 20, 2007 Page 154 of 638
REJ09B0395-0400
Bit
Initial value
Read/Write
⎯
⎯
7
1
Reserved bits
⎯
⎯
6
1
4
functions as the CS
⎯
⎯
5
1
R/W
P8
4
0
4
0
output, while CS
R/W
P8
3
0
Port 8 data 4 to 0
These bits store data
for port 8 pins
3
R/W
P8
2
0
2
1
to CS
R/W
P8
1
0
3
1
are input ports.
R/W
P8
0
0
0