SI549 - OE not connected to SI57X_SEC_OE.

OE of SI549 (pin 1) is not connected to SI57X_SEC_OE signal.

The 0R resistor should be added to make this connection (similarly like in Kasli project).

assigned to @tprzywoz

changed title from SI549 wrong PN - OE signal on pin 1 instead of pin 2. to SI549 - OE not connected to SI57X_SEC_OE.

changed the description

changed milestone to %AFC v4.1

changed milestone to %AFC v4.0.2

I've placed R474 and R449 jumpers. Now it should work with OE signal on 1st or 2nd pin

mentioned in issue #188 (closed)

Actually, isn't it too complicated? In original version you could enable Si549 with SI57X_SEC_TUNE/SYNC signal. So in my opinion we should either revert changes, or remove one of these two signals: SI57X_SEC_OE, SI57X_SEC_TUNE/SYNC as they are redundant.

mentioned in issue #193 (closed)

closed

SI57X_SEC_OE and SI57X_SEC_TUNE/SYNC are not redundant. The SI57X_SEC_TUNE/SYNC line was intended to sync DAC or tune the SI571 oscillator by PWM directly from FPGA. By removing SI57X_SEC_TUNE/SYNC line you lost the ability of tuning the SI571 by PWM from FPGA.

Possible functions of pin 1 and 2 due to the oscillator used:

	SI549	SI570	SI571
Pin 1	(n)OE or nc	nc	VC
Pin 2	(n)OE or nc	OE	OE

When using SI571 pin 1 (VC) can be driven by:

• DAC (net PLLDAC_OUT2)
• PWM from FPGA + RC filter (net SI57X_SEC_TUNE/SYNC)

Maybe it would be good to keep all the tuning options for SI571 as well as OE connection to pin 1 and 2 for SI549.

What's more, I just noticed that in case of primary oscillator the OE signal is connected only to pin 2. When using SI57x it's OK, but it would be good to add the optional connection to pin 1 for SI549. It seems just the 0R between pin 1 and 2 will do the job.

I think this kind of universality is worth to be done, especially when availability of components like Silabs oscillators is, let's say, temporary limited.

reopened

assigned to @Filip.Switakowski and unassigned @tprzywoz

So, I made this for OSC2:

and to be consistent, OSC1:

closed

Now it looks good, thanks.

Only one detail - R384 and R224 are set as 0R shorts, while they are actually the parts of low pass filter - when SI57X_(PRI)SEC_TUNE/SYNC lines are being used as PWM.