EM78P809N
8-Bit Microcontroller
Product Specification (V1.0) 07.26 .2 005 39
(This specification is subject to change without further notice) SPISRBFWBESPIF
read data
shift start shift start
/SCK pin
SI p i n c0 c1 c2 c3 c4 c5 c 6 c7
a
SPID
d0 d1 d2 d3 d4 d5 d6 d7
read dat a
d
shift finish
SO pi n a0 a 1 a2 a3 a4 a5 a6 a7 b0 b1 b2 b3 b4 b5 b6 b7
shift finish
c
write data
b
write data

Fig. 17. Transmit/Receive Mode (8-bit, 1 word)

(d) Multiple Device Connect (/SS):

When selecting external clock for transfer clock source, the /S S function can be

used. This pin (/SS) will be active when the /SS function is enabled, else the /SS

pin is a general purpose I/O. Ignore the data on the SDI and SDO pins while /SS

is high, since the SDO is no longer driven.

Master

SDI
P.67
P 65
P 64
SDO
SDI
SCK
/SS

Master

SDI
SDO
SCK
/SS

Slave Device 1

P67
P66
P65
P64
SDI
SDI
SDO
SCK
/SS

Slave Device 2

SDI
SDI
SDO
SCK
/SS

Slave Device 3

SDI
SDI
SDO
SCK
/SS

Slave Device 4

Fig. 18. The SPI Configuration Example of Single-Master and Multi-Slaves