Manu Martinez

iMX286 custom board: need some hints.

Discussion created by Manu Martinez on Dec 18, 2011

I've just beginning to design a iMX286 custom board taking as reference the EVK schematics and layout. I hope someone with previous experience in this matter can give some hints about:

1. I will use: 2xUSB, 1xETH, 2xCAN, 24bit LCD and 8xGPIO. With this amount of nets and using 4 layer, 4mil track/space and 8mil/16mil vias I can do the fanout without problems. However I still concerned about the convenience or not to use 6L and so to fill a layer only with power planes. Have any of you manufactured a 4L board without EMC problems?

2. I can see DDR EMI_A13 and EMI_A14 nets connected in the EVK schematics. Why? The memory has 1Gb not 4Gb... Besides I can see those pins as NC  on the EDE1116AEBG datasheet.

3.  How do I place the DDR decoupling capacitors?. There are 16 power pins (VDD, VDDQ and VDDL) and I can see 13 capacitors with different values (0.01, 0.1, 0.22 and 10uF). I really don't know how to link them.