Hello,
We are using the C6711D in our product and we meet a rate of 20 to 40% of unsuccesfull starts.
Our software boot in internal flash on a boot loader witch load the firmware in RAM. The first instruction of our boot is to set at 1 the pin Timer1 TOUT1.
The electrical reset is managed by the device (LTC2901) which asserts a reset with 150ms duration. This device is also an external watchdog refreshed by C6711D pin Timer1 TOUT1.
On unsuccesfull starts :
- After reset, we have the 7.5MHz on the clock-out pin with CLKIN at 20MHz.
- Timer1 TOUT1 pin stay at 0.
It seems the boot mode selection is not stable. The issue seems to be hardware issue. Which could be the root causes ?
For information, we added the following pullup and pulldown :
- HD4 : pulldown 1K
- HD8 : pullup 1K
- HD12 : pullup 1K
- RESET : pullup 1K
- CLKMODE0 : pullup
Many thanks for your help.