FEDL2302DIGEST-05

OKI Semiconductor

ML2302

13/24

FIFO Memory Configuration

The ML2302 has two FIFO memories; one is for recording and other is for playback.

The configuration of FIFO memory can be changed with a command. Select a FIFO configuration considering

buffering times.

Initially, FIFO memory for recording and FIFO memory for playback each is provided with 1024 bits (128 words

× 8 bits).

ML2302 cannot command recording and playback at the same time.

1. Combination of FIFO memory capacities

Table 1.3.1 shows the combination of FIFO memory capacities in recording and playback modes.

Table 1.3.1

Mode

Capacity

Recording

Playback

1024 bits

128 w

× 8 bits

128 w

× 8 bits

*Initial value

512 bits

64 w

× 8 bits

64 w

× 8 bits

256 bits

32 w

× 8 bits

32 w

× 8 bits

2. Voice synthesis algorithms and maximum buffering times

Table 1.3.2 shows the maximum buffering times when the FIFO capacity is 1024 bits and the sampling frequency

is 8 kHz.

Table 1.3.2

Mode

Voice

synthesis algorithm

Recording

Playback

4-bit OKIADPCM

32 ms

32 ms

4-bit OKIADPCM2

32 ms

32 ms

5/6/7/8-bit OKIADPCM2

16 ms

16 ms

2-bit OKIADPCM2

64 ms

64 ms

8-bit straight PCM

16 ms

16 ms

16-bit straight PCM

8 ms

8 ms

8-bit OKI Non-linear PCM

Note)

16 ms

Note: The 8-bit OKI Non-linear PCM algorithm cannot be used during recording.