Hitachi H8/3637 Hardware Manual page 62

To avoid this problem, store a copy of the PDR6 data in a work area in memory. Perform the bit
manipulation on the data in the work area, then write this data to PDR6.
[A: Prior to executing BSET]
MOV. B #80,
MOV. B R0L,
MOV. B R0L,
P6
7
Input/output Input
Pin state Low
level
PCR6 0
PDR6 1
RAM0 1
[B: BSET instruction executed]
BSET #0,
[C: After executing BSET]
MOV. B @RAM0, R0L
MOV. B R0L,
P6
7
Input/output Input
Pin state Low
level
PCR6 0
PDR6 1
RAM0 1
52
R0L
The PDR6 value (H'80) is written to a work area in
@RAM0
memory (RAM0) as well as to PDR6.
@PDR6
P6 P6
6 5
Input Output
High Low
level level
0 1
0 0
0 0
@RAM0
The BSET instruction is executed designating the PDR6
work area (RAM0).
The work area (RAM0) value is written to PDR6.
@PDR6
P6 P6
6 5
Input Output
High Low
level level
0 1
0 0
0 0
P6 P6 P6
4 3
Output Output
Low Low
level level
1 1
0 0
0 0
P6 P6 P6
4 3
Output Output
Low Low
level level
1 1
0 0
0 0
P6 P6
2 1
Output Output Output
Low Low Low
level level level
1 1 1
0 0 0
0 0 0
P6 P6
2 1
Output Output Output
Low Low High
level level level
1 1 1
0 0 1
0 0 1
0
0