FUJITSU MHD2032AT - Manual (Page 181)

Operations
6-2 C141-E050-02EN
6.1 Device Response to the Reset
This section describes how the PDIAG- and DASP- signals responds when the
power of the IDD is turned on or the IDD receives a reset or diagnostic command.
6.1.1 Response to power-on
After the master device (device 0) releases its own power-on reset state, the master
device shall check a DASP- signal for up to 450 ms to confirm presence of a slave
device (device 1). The master device recognizes presence of the slave device
when it confirms assertion of the DASP- signal. Then, the master device checks a
PDIAG- signal to see if the slave device has sucessfully completed the power-on
diagnostics.
If the master device cannot confirm assertion of the DASP- signal within 450 ms,
the master device recognizes that no slave device is connected.
After the slave device (device 1) releases its own power-on reset state, the slave
device shall report its presence and the result of power-on diagnostics to the
master device as described below:
DASP- signal: Asserted within 400 ms.
PDIAG- signal: Negated within 1 ms and asserted within 30 seconds.