CM4 vs CM5 — a curious DFT difference

We mapped the test points on both Raspberry Pi Compute Modules and found an interesting difference.

CM5 gives you direct access to power, USB, boot control, UART, and Ethernet — enough to build a pogo-pin fixture for flashing and production testing.

CM4 has plenty of test points too, but we couldn’t find USB, 5 V, or boot control among them.

So what were the CM4 test points actually designed for? Factory testing? Direct eMMC access? Something else?

Check out interactive testpoint maps for these SoMs:
CM5 → https://everypinio.github.io/cm5-flash-jig/test-points/cm5/
CM4 → https://everypinio.github.io/cm5-flash-jig/test-points/cm4/

Same idea. Two generations. Very different approach to DFT.

If you need robust flashing solution for CM4 or CM5 check here (https://bit.ly/4zUaHcx)

#Everypin #RaspberryPi #CM4 #CM5 #DesignForTest #HardwareTesting #TestFixture #PogoPins