HD64F3048F16 Datasheet, PDF (299/903 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 9 I/O Ports
Port 3 Data Direction Register (P3DDR)
P3DDR is an 8-bit write-only register that can select input or output for each pin in port 3.
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0
P3₇DDR P3₆DDR P3₅DDR P3₄DDR P3₃DDR P3₂DDR P3₁DDR P3₀DDR
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
Port 3 data direction 7 to 0
These bits select input or output for port 3 pins
Modes 1 to 6 (Expanded Modes): Port 3 functions as a data bus. P3DDR is ignored.
Mode 7 (Single-Chip Mode): Port 3 functions as an input/output port. A pin in port 3 becomes an
output port if the corresponding P3DDR bit is set to 1, and an input port if this bit is cleared to 0.
P3DDR is a write-only register. Its value cannot be read. All bits return 1 when read.
P3DDR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode
it retains its previous setting. If a P3DDR bit is set to 1, the corresponding pin maintains its output
state in software standby mode.
Port 3 Data Register (P3DR)
P3DR is an 8-bit readable/writable register that stores output data for pins P3₇ to P3₀. While port 3
acts as an output port, the value of this register is output. When a bit in P3DDR is set to 1, if port 3
is read the value of the corresponding P3DR bit is returned. When a bit in P3DDR is cleared to 0,
if port 3 is read the corresponding pin level is read.
Bit
Initial value
Read/Write
7
P3 ₇
0
R/W
6
5
4
3
2
1
0
P3 ₆
P3 ₅
P3 ₄
P3 ₃
P3 ₂
P3 ₁
P3 ₀
0
0
0
0
0
0
0
R/W
R/W
R/W R/W
R/W
R/W R/W
Port 3 data 7 to 0
These bits store data for port 3 pins
P3DR is initialized to H'00 by a reset and in hardware standby mode. In software standby mode it
retains its previous setting.
Rev. 3.00 Sep 27, 2006 page 271 of 872
REJ09B0325-0300