Hi,
difference between NOSEQ high/low is only the enable of 1V and 1V8V:
- https://wiki.trenz-electronic.de/display/PD/TE0720+TRM#TE0720TRM-Power-OnSequence (https://wiki.trenz-electronic.de/display/PD/TE0720+TRM#TE0720TRM-Power-OnSequence)
In case of NOSEQ high, they will be enabled, if VIN is available (over SN74LVC1G97 (U21 and U25 on schematic)):
In case NOSEQ is low (CPLD check power):
CPLD controlls enable Pin:
- ON_1V0, if EN1 is set(with small register delay (~25MHz internal CLK))
- ON_1V8, if PG_1V0 and EN1_g is set(with small register delay (~25MHz internal CLK))
- ON_1V5, if PG_1V0 and PG_1V8 and EN1_g is set(with small register delay (~25MHz internal CLK))
- EN_3V3, if PG_1V0 and PG_1V8 and EN1_g is set(with small register delay (~25MHz internal CLK))
So in any case CPLD must be powered with 3.3V.
But I've no information about exact delay from 3.3VIN, VIN and power on of all regulators of the module.
PGOOD is low, if EN1 is low or the RESIN Pin.
In case you will supply Bank IOs, use the 3.3Vout or the 1.8Vout of the module to enable your bank power (for example with power switch). PGOOD is only monitoring and should not be used to enable Bank powers.
Some basics of the 4x5 modules:
- https://wiki.trenz-electronic.de/display/PD/4+x+5+SoM+Integration+Guide
br
John