ml87v5002 Oki Semiconductor, ml87v5002 Datasheet - Page 12

• Manufacturer Part Number: ml87v5002
• Description: Audio Delay Ic With Built-in 2-mbit Dram
• Manufacturer: Oki Semiconductor

Reading pointer
before the change
There are two options, “restart by a command” and “auto-restart”, for restarting the delay operation by setting the
internal register.
In the case of the “restart by a command”, the INT output is set at “L” at athe same time as error detection. The
delay operation is restarted by removing the cause of the error and writing “1” to the “ENBL” bit.
In the case of the “auto-restart” option (the internal register AUTORSTRT (SUB 07h-bit[1] = “1”), if the
suspension is due to an error [TMG_ERR, OVRN, or UDRN] excluding CFG_ERR and BCK_ERR, set the error
bit to “1” to restart the delay operation. (In this case, this LSI does not set the INT output at “L” or not generate the
interrupt even if the interrupt mask register is cleared.)
In the case of the “auto-restart” option, if an error is detected and CFG_ERR or BCK_ERR is set to “1”, the LSI
clears the ENBL bit to “0” and stops the delay operation. (In this case, this LSI sets the INT output at “L” and
generates the interrupt if the interrupt mask register has been cleared.) Since the error bit is not automatically
cleared, the host CPU writes “0” to the corresponding bit and clears the error bit.
When the newly set value of the delay time is less than the previously set value, the reading pointer is moved
forward and the operation is performed with a new delay time. In this case, the data existing between the times
before and after the change is not output phonetically. (Figure 10)
Meanwhile, when the newly set value is longer than the former set value, the reading pointer should be moved
backward and the operation should be performed with a new delay length. Output is muted (“0” output) for the
insufficient data (Figure 11).
OKI Semiconductor
Restart of delay operation (restart by a command / auto-restart)
Change of the delay parameters during the delay operation
Reading pointer
before the change
This data is not output phonetically.
Figure 10 When a delay time is changed (when the delay time is
Figure 11 When a delay time is changed (when the delay time is
Insufficient data
Silence is output.
shorter than the previously set time.)
longer than the previously set time.)
Reading pointer
after the change
Reading pointer
after the change
Current data
Current data
Proceeding direction of the pointer
Proceeding direction of the pointer
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