2. CPU
Rev.3.00 Jul. 19, 2007 page 68 of 532
REJ09B0397-0300
As a result of this operation, bit 0 in PCR3 becomes 0, making P3
0
an input port. However, bits 7
and 6 in PCR3 change to 1, so that P3
7
and P3
6
change from input pins to output pins.
To avoid this problem, store a copy of the PCR3 data in a work area in memory. Perform the bit
manipulation on the data in the work area, then write this data to PCR3.
[A: Prior to executing BCLR]
MOV. B #3F, R0L
MOV. B R0L, @RAM0
MOV. B R0L, @PCR3
The PCR3 value (H'3F) is written to a work area in memory
(RAM0) as well as to PCR3.
P3
7
P3
6
P3
5
P3
4
P3
3
P3
2
P3
1
P3
0
Input/output Input Input
Output Output Output Output Output Output
Pin state
Low
level
High
level
Low
level
Low
level
Low
level
Low
level
Low
level
Low
level
PCR3
0 0 1 1 1 1 1 1
PDR3
1 0 0 0 0 0 0 0
RAM0
0 0 1 1 1 1 1 1
[B: BCLR instruction executed]
BCLR #0 , @RAM0
The BCLR instruction is executed designating the PCR3
work area (RAM0).
[C: After executing BCLR]
MOV. B @RAM0, R0L
MOV. B R0L, @PCR3
The work area (RAM0) value is written to PCR3.
P3
7
P3
6
P3
5
P3
4
P3
3
P3
2
P3
1
P3
0
Input/output Input Input
Output Output Output Output Output Output
Pin state
Low
level
High
level
Low
level
Low
level
Low
level
Low
level
Low
level
High
level
PCR3
0 0 1 1 1 1 1 0
PDR3
1 0 0 0 0 0 0 0
RAM0
0 0 1 1 1 1 1 0
Summary of Contents for F-ZTAT H8 Series
Page 6: ...Rev 3 00 Jul 19 2007 page iv of xxiv REJ09B0397 0300...
Page 194: ...7 RAM Rev 3 00 Jul 19 2007 page 168 of 532 REJ09B0397 0300...
Page 234: ...8 I O Ports Rev 3 00 Jul 19 2007 page 208 of 532 REJ09B0397 0300...
Page 274: ...9 Timers Rev 3 00 Jul 19 2007 page 248 of 532 REJ09B0397 0300...
Page 352: ...12 A D Converter Rev 3 00 Jul 19 2007 page 326 of 532 REJ09B0397 0300...
Page 561: ......
