Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

USB EZ-PD™ Type-C Forum Discussions

NiMc_4245981
Level 3
10 replies posted 10 questions asked 5 replies posted
Level 3

The DataSheet for the CCG4 says there are 4 ADCs (Figure 2), but each ADC can only connect to 2 global analog multiplex busses.

Does this mean only 2 of the ADCs are useful?

Or, are there really 4 global analog multiplex busses on the CCG4?  If so, how do I specify which USB-PD subsystem a GPIO pin should connect to?

I'm looking at the notebook example firmware.  Both VBUS_MON_P1 and VBUS_MON_P2 are connected to AMUXA.  I don't understand why this isn't a conflict.

0 Likes
1 Solution
YiZ_31
Moderator
Moderator 1000 replies posted 750 replies posted 500 replies posted
Moderator

Hi,

I'm sorrt my former reply was incorrect. Each port has two AMUX(AMUXA and AMUXB). Which means CCG4 has totally 4 AMUX. However, each port can only access two of them.


Regards,
Eddie

View solution in original post

0 Likes
3 Replies
YiZ_31
Moderator
Moderator 1000 replies posted 750 replies posted 500 replies posted
Moderator

Hi,

Each USB-PD sub-system of CCG4 contains two 8-bit SAR ADCs. Figure 2 is for CCG4 that have two Type-C Ports. There are some types of CCG4 only have one Type-C port.

pastedImage_3.png

There are only two globa AMUX. When doing voltage measurement, AMUX will switch to the right Pin with High-speed I/O matrix(HSIOM).

Regards,
Eddie

0 Likes
NiMc_4245981
Level 3
10 replies posted 10 questions asked 5 replies posted
Level 3

I'm using the CYPD4225, which has two ports.

I'm still confused how the right pin is selected.  Both VBUS_MON_P1(pin 13) and VBUS_MON_P2(pin 25) are selected to HSIOM_MODE_AMUXA in system_init().

Then, in vbus_is_present() the voltage is sampled by calling pd_adc_comparator_sample() with PD_ADC_INPUT_AMUX_A for the input.  At this point, both pins have been connected to AMUXA and nothing seems to indicate which one should be sampled.  How does this work?

0 Likes
YiZ_31
Moderator
Moderator 1000 replies posted 750 replies posted 500 replies posted
Moderator

Hi,

I'm sorrt my former reply was incorrect. Each port has two AMUX(AMUXA and AMUXB). Which means CCG4 has totally 4 AMUX. However, each port can only access two of them.


Regards,
Eddie

0 Likes