NEC PD17062 - Manual (Page 99)

99
µ
PD17062
10.5.3 Presettable Shift Register
Fig. 10.6 shows the functions of the presettable shift register.
The presettable shift register writes the serial interface serial out data and reads the serial interface serial
in data.
Fig. 10-6 Relationship between Presettable Shift Register and Data Buffer
Serial interface serial data is output while being shifted sequentially the data from the MSB (bit b 7 ) of the
presettable shift register.
During serial data input, data is shifted sequentially from the LSB (bit b 0 ).
DBF3
0CH
DBF2
0DH
DBF1
0EH
DBF0
0FH
b
15
b
14
b
13
b
12
b
11
b
10
b
9
b
8
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
D7 D6 D5 D4 D3 D2 D1 D0
SIO0SFR 03H
Serial out data write and serial in data read
1 2 3 4 5 6 7 8
MSB LSB
Data output timing
× D7 × D6 × D5 × D4 × D3 × D2 × D1 × D0
1 2 3 4 5 6 7 8
MSB LSB
Data input timing
×
D7
×
D6
×
D5
×
D4
×
D3
×
D2
×
D1
×
D0
8
Symbol
Peripheral
address
Peripheral hardware Name
Peripheral register
Name Data buffer
Symbol
Address
Bit
Data Don't care Don't care Transfer data
GET
PUT
Valid data
Presettable
shift register
Serial interface
Serial out data
Clock
Serial in data
Clock