ml2251 Oki Semiconductor, ml2251 Datasheet - Page 20

• Manufacturer Part Number: ml2251
• Description: 2-channel Mixing Oki Adpcm Algorithm-based Speech Synthesis Lsi
• Manufacturer: Oki Semiconductor

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.
Table below shows the SERIAL pin status in the serial and parallel interfaces.
1. Parallel Interface
Command and Data Input Timing
OKI Semiconductor
When selecting the parallel interface, the I/O pins CS, WR, DW, D7 to D0, and RD 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 CS 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 WR pin.
The DW pin is used to input data after having input the EXT or Flash I/F command. The method to input data
to the DW pin is the same as the method to input command from the WR pin.
To read the channels status, pins CS and RD are made “L” level. By doing so, the status signals (NCR1, NCR2,
BUSY1, BUSY2) of each channel are output to D3 through D0 pins. D7 to D4 pins usually output “L” level.
D7 (I/O)
D6 (I/O)
D5 (I/O)
D4 (I/O)
D3 (I/O)
D2 (I/O)
D1 (I/O)
D0 (I/O)
SERIAL pin = "H" level: Serial interface
SERIAL pin = "L" level: Parallel interface
D7 to D0 (I/O)
WR , DW (I)
Data input/output pins
Parallel interface
SERIAL = “L”
CS (I)
Data Stable
SCK (I)
DO (O)
D4 (I)
D3 (I)
D2 (I)
D1 (I)
D0 (I)
D (I)
Serial data input pin
Serial clock input pin
Serial data output pin
Not used. (Input “L” level.)
Not used. (Input “L” level.)
Not used. (Input “L” level.)
Not used. (Input “L” level.)
Not used. (Input “L” level.)
Serial interface
SERIAL = “H”
FEDL2250DIGEST-06
ML2250 family
20/35