Data Direction Register - Fujitsu MB90390 Series Hardware Manual

CHAPTER 10 I/O PORTS
10.2.2

Data Direction Register

When a pin is used as a port, the corresponding pin is controlled as described below:
0: Input mode
1: Output mode
■ Data Direction Register
Figure 10.2-3 shows the data direction registers.
DDR0
Address: 000010
DDR1
Address: 000011
DDR2
Address: 000012
DDR3
Address: 000013
DDR4
Address: 000014
DDR5
Address: 000015
DDR6
Address: 000016
DDR7
Address: 000017
DDR8
Address: 000018
DDR9
Address: 000019
DDRA
Address: 00001A
DDRB
Address: 00001B
■ Reading the Data Direction Register
The Data Direction Register can be read independently from the status of the corresponding resource.
However, the value of the DDR influences the result of a read access on the Port Data Register.
174
Figure 10.2-3 Data Direction Registers
bit 7 6 5
D07 D06 D05
H
15 14 13
D17 D16 D15
H
7 6 5
D27 D26 D25
H
15 14 13
D37 D36 D35
H
7 6 5
D47 D46 D45
H
15 14 13
D57 D56 D55
H
7 6 5
D67 D66 D65
H
15 14 13
D77 D76 D75
H
7 6 5
D87 D86 D85
H
15 14 13
D97 D96 D95
H
7 6 5
DA7 DA6 DA5
H
15 14 13
DB7 DB6 DB5
H
4 3 2 1
D04 D03 D02 D01
12 11 10 9
D14 D13 D12 D11
4 3 2 1
D24 D23 D22 D21
12 11 10 9
D34 D33 D32 D31
4 3 2 1
D44 D43 D42 D41
12 11 10 9
D54 D53 D52 D51
4 3 2 1
D64 D65 D62 D61
12 11 10 9
D74 D73 D72 D71
4 3 2 1
D84 D83 D82 D81
12 11 10 9
D94 D93 D92 D91
4 3 2 1
DA4 DA3 DA2 DA1
12 11 10 9
DB4 DB3 DB2 DB1
0 Initial value Access
00000000 R/W
D00
B
8
00000000 R/W
D10
B
0
00000000 R/W
D20
B
8
00000000 R/W
D30
B
0
00000000 R/W
D40
B
8
00000000 R/W
D50
B
0
00000000 R/W
D60
B
8
00000000 R/W
D70
B
0
00000000 R/W
D80
B
8
00000000 R/W
D90
B
0
00000000 R/W
DA0
B
8
00000000 R/W
DB0
B