NEC mPD17120 Subseries, User Manual

Page: 156 / 289

CHAPTER 13 PERIPHERAL HARDWARE
141
13.3.3 Setting Values in the Shift Register
Values are set in the shift register via the data buffer (DBF) using the PUT instruction.
The peripheral address of the shift register is 01H. When sending a value to the shift register using the PUT
instruction, only the low-order eight bits (DBF1, DBF0) of DBF are valid. The DBF3 and DBF2 values do not affect
the shift register.
Figure 13-16. Setting a Value in the Shift Register
Example of setting value 64H in the shift register
SIODATL DAT 4H ; SIODATL is assigned to 4H using symbol definition.
SIODATH DAT 6H ; SIODATH is assigned to 6H using symbol definition.
MOV DBF0, #SIODATL ;
MOV DBF1, #SIODATH ;
PUT SIOSFR, DBF ; Value is transmitted using reserved word SIOSFR.
PUT SIOSFR,DBF
SIOSFR (Peripheral Address 01H)
Data Buffer
DBF3
Don't care
8-bit data
b
7
0
b
5
1
b
4
0
b
3
0
b
2
1
b
1
0
b
0
0
b
6
1
b
0
0
b
1
0
b
2
1
b
3
0
b
0
0
b
1
1
b
2
1
b
3
0
b
0
b
1
b
2
b
3
b
0
b
1
b
2
b
3
DBF2
Don't care
DBF1 DBF0