FEDL2250DIGEST-09

OKI Semiconductor

ML2250 family

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FUNCTIONAL DESCRIPTION

Micro-computer Interface

The micro-computer interface in the ML2250 family has 2 types of interface circuits built in: Parallel interface and

serial interface. The interface setting can be changed with the SERIAL pin.

SERIAL pin = "H" level: Serial interface

SERIAL pin = "L" level: Parallel interface

Table below shows the SERIAL pin status in the serial and parallel interfaces.

SERIAL =

“L”

SERIAL =

“H”

Parallel interface

Serial interface

D7 (I/O)

D (I)

Serial data input pin

D6 (I/O)

SCK (I)

Serial clock input pin

D5 (I/O)

DO (O)

Serial data output pin

D4 (I/O)

D4 (I)

Not used. (Input

“L” level.)

D3 (I/O)

D3 (I)

Not used. (Input

“L” level.)

D2 (I/O)

D2 (I)

Not used. (Input

“L” level.)

D1 (I/O)

D1 (I)

Not used. (Input

“L” level.)

D0 (I/O)

Data input/output pins

D0 (I)

Not used. (Input

“L” level.)

1. Parallel Interface

When selecting the parallel interface, the I/O pins ÝÍ, ÉÎô ÜÉ, D7 to D0, and ÎÜ 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 input.

The micro-computer interface becomes effective when the ÝÍ pin is set to “L” level.

When a command or data is input, the input data to D7 through D0 pins is captured inside the device on the

rising edge of the ÉÎ pin.

The ÜÉ pin is used to input data after having input the EXT or Flash I/F command. The method to input data to

the ÜÉ pin is the same as the method to input command from the ÉÎ pin.

To read the channels status, pins ÝÍ and ÎÜ are made “L” level. By doing so, the status signals (NCR1, NCR2,

ÞËÍÇï

, ÞËÍÇî) of each channel are output to D3 through D0 pins. D7 to D4 pins usually output “L” level.

Command and Data Input Timing

Data Stable

CS

(I)

WR

, DW (I)

D7 to D0 (I/O)