FEDL2240DIGEST-02

OKI Semiconductor

ML2240 Family

13/24

2. Serial Interface

When selecting the serial interface, the I/O pins

CS, WR, DI. SCK, RD, and DO are used as input pins to input

various commands and data, and as output pins to read out the status of the commands and data.

The micro-computer interface becomes effective when

CS pin is set to “L” level.

To input the commands and data, “L” level is input to

CS and WR pins followed by, from MSB, to DI pin in

synchronization with the input clock signal at SCK pin. Data at DI pin is captured inside the device on the

rising or falling edge of the clock at SCK pin. And the command is executed on the rising edge of the

WR pin.

The selection of rising/falling edge of SCK clock is determined by the input level of the SCK pin on the falling

edge of the

CS pin. If the SCK pin on the falling edge of the CS pin is at “L” level, the DI pin data is captured

inside the device on the rising edge of SCK clock. Conversely, if the SCK pin on the falling edge of the

CS pin

is at “H” level, then the DI pin data is captured on the falling edge of SCK clock.

Command and Data Input Timings

• SCK Rising Edge Operation

• SCK falling Edge Operation

DI (I)

CS (I)

WR (I)

D7

SCK (I)

D6

D5

D4

D3

D2

D1

D0

CS (I)

WR (I)

D7

SCK (I)

D6

D5

D4

D3

D2

D1

D0

DI (I)