SM5921A

SEIKO NPC CORPORATION —13

Output Enable (OEN pin)

The SM5921A has an output enable control for the DOA, DOB, DOC, DOD outputs. When OEN is HIGH, the

output pins are disabled. The OEN pin has a pull-down resistor built-in. When the OEN pin is open-circuit (or

LOW), the output pins are enabled and delay data is output. The OEN pin is detected on the WCKI boundary

edge, which means that there is a maximum 1-word delay before the change is reflected at the output.

Direct Mute (DMUTEN pin)

Direct mute ON/OFF

Other mute operations

The outputs are also muted (direct mute) when a reset pulse is applied.

The outputs are also muted (direct mute) when the INIT flag is set.

The outputs are also muted (direct mute) when the PDW flag is set.

The outputs are also muted (direct mute) setting the delay data values.

DMUTEN

Function

LOW

0 data output from the next output word after writing the setting.

HIGH

Normal delay data output from the next output word after writing the setting.

RSTN

Function

LOW

0 data output from the next output word after writing the setting.

HIGH

Normal delay data output after 64 output words after writing the setting.

INIT

Function

LOW

Normal output operation.

HIGH

Normal delay data output after a 64-word mute interval after writing the setting.

PDW

Function

LOW (HIGH

→ LOW)

0 data output from the next output word after writing to the register. The outputs are muted during the interval until the

initialization data write point, and then mute is released for delay data output.

HIGH

0 data output from the next output word after writing data to the register.

Delay setting

Function

Intrinsic delay

0 data output from the next output word after writing to registers REG 0/H and 1/H. The outputs are muted during the

interval until the initialization data write point, and then mute is released for delay data output.

Individual delay

0 data output from the next output word after writing to registers REG 3/H to 9/H. The outputs are muted during the

interval until the initialization data write point, and then mute is released for delay data output.