r8a66156sp Renesas Electronics Corporation., r8a66156sp Datasheet - Page 2

• Manufacturer Part Number: r8a66156sp
• Description: 24-bit I/o Expander With Led Drive Function
• Manufacturer: Renesas Electronics Corporation.

R8A66156SP
BLOCK DIAGRAM
FUNCTION
The R8A66156 is produced by using the silicon gate CMOS technology and has low power dissipation and
high noise margin.
Built in two shift registers for serial in-parallel out (Shift register 2) and parallel in-serial out (Shift register 1)
are constructed independently, R8A66156 is able to read serial input data into a shift register while output
the serial data converting from the parallel data input.
Serial output operation of 24-bit parallel latched data and serial input operation from MCU are started when
/CS is changed from "H" to "L".
24-bit parallel data are latched by the negative edge of /CS and are output from the DO terminal
synchronously to the negative edge of CLK, and also the DI terminal read serial input data from MCU and
are written into the internal shift register 2.
The 25th and following shift clock pulse are ignored and serial input data is masked, and DO terminal
becomes high-impedance ("High-Z").
When /CS is changed from "L" to "H", 24-bit serial data which is read from the DI terminal are output to the
D1~D24 terminals as parallel data.
As the output circuit type of D1~D24 terminals is N-ch open drain output, write data "H" for pins which should
be set to input mode.
REJ03F0283-0100 Rev.1.00 Sep.14.2009
Page 2 of 7
CLK
CS
S
DI
5
9
7
3
Q
Q
D
D
DI
24
24
24
24
D
Q
D
Q
Parallel output latch
23
23
23
23
Shift register 1
Shift register 2
D
Q
D
Q
GND
22
22
22
22
1
GND GND
6
Q
D
Q
D
3
3
3
3
10
D
D
Q
Q
2
2
2
2
DO
D
D
Q
Q
Vcc
GND GND
1
1
4
1
1
19
Vcc
28
8
36
35
34
13
12
11
2
D
D
D
DO
D
D
D
22
23
24
1
2
3
CLK, S, CS, DI
Output
.
Vcc
DO
Output Type
Input type
Vcc
S
Inout
Vcc
D
1
～D
24