Hi,
As many of users faced problems with CLK line, for which solution was to remove CLK resistor between CPU and eMMC chip on target board, here is simple solution to overcome this problem:
For RIFF Box v1 (black box):
- Add pull up resistor from VCCQ (1.8v) to CLK line
Value starting from 4.7K (worked on qualcomm) down to100 Ohms (for some MTK). Its better to start from 4.7K and test with decreasing value until successful connection is established.
...
Following schematics can be used for both v1 and v2 box, two variants with
different IC-s (buffers/line drivers)
SN74LVC1G34 and SN74LVC1G125
4.7 K resistor is optional, in case that on some boards stronger drive is required, pull up resistor value can be determined by experimenting with as low as 200 Ohms.
As many of users faced problems with CLK line, for which solution was to remove CLK resistor between CPU and eMMC chip on target board, here is simple solution to overcome this problem:
For RIFF Box v1 (black box):
- Add pull up resistor from VCCQ (1.8v) to CLK line
Value starting from 4.7K (worked on qualcomm) down to100 Ohms (for some MTK). Its better to start from 4.7K and test with decreasing value until successful connection is established.
...
Following schematics can be used for both v1 and v2 box, two variants with
different IC-s (buffers/line drivers)
SN74LVC1G34 and SN74LVC1G125
4.7 K resistor is optional, in case that on some boards stronger drive is required, pull up resistor value can be determined by experimenting with as low as 200 Ohms.
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