PSoC6 ADC

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

cross mob
acheesehead
Level 1
Level 1
First solution authored 5 sign-ins First reply posted

I am using a CY8C6247BZI-D54 and PSoC Creator 4.4. Trying to configure the ADC and am getting strange results. I am using single-ended inputs and configured to Vdda and Vssa. The voltage range says 0 to 3.3V and dialog says 12 bits. But, the SE bit range shows 0 to 0x7ff. I would expect 0 to 0xfff. I have experimented with different settings and get the same results.

Thoughts?

Thanks,

Todd

acheesehead_0-1646860489170.png

 

0 Likes
1 Solution
Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hi Todd,

For single-ended mode with VMINUS connected to VSSA, conversions are effectively 11-bit because voltages cannot swing below VSSA on any PSoC 6 MCU pin. Because of this, the global configuration bit SINGLE_ENDED_SIGNED (SAR_SAMPLE_CTRL[2]) will be ignored and the result is always (0x000-0x7FF). See the table below.

Vasanth_0-1646889368295.png

Best Regards,
Vasanth

 

View solution in original post

2 Replies
Len_CONSULTRON
Level 9
Level 9
Beta tester 500 solutions authored 1000 replies posted

Todd from WI,

You are correct.  A 12-bit code unsigned range is 0x00 to 0xFFFF.   = (2^12) -1 = 0v0000 1111 1111 1111

Len
"Engineering is an Art. The Art of Compromise."
0 Likes
Vasanth
Moderator
Moderator
Moderator
250 sign-ins 500 solutions authored First question asked

Hi Todd,

For single-ended mode with VMINUS connected to VSSA, conversions are effectively 11-bit because voltages cannot swing below VSSA on any PSoC 6 MCU pin. Because of this, the global configuration bit SINGLE_ENDED_SIGNED (SAR_SAMPLE_CTRL[2]) will be ignored and the result is always (0x000-0x7FF). See the table below.

Vasanth_0-1646889368295.png

Best Regards,
Vasanth