Hi all,

I'm getting 'Unable to read IdCode' errors when I try and enter debug mode on a LPC2387.

It's a new install of Ride/Rkit, everything works great on a STM32F board and I've tried multiple RLINK devices.

However, when I go to RLink configuration -> advanced options, I can 'Check connection to target' (it gives IdCode = 0x4F1F0F0F), erase device and (frequently) write target flash. Occasionally trying to write the target flash also gives 'Unable to read IdCode' errors. Trying to enter debug mode always gives debug errors.

All I can think is that there is a problem either with the JTAG layout on the 2387 board, or an error in the RLink driver. The 2387 board is a custom design, I can provide schematics if necessary.

The JTAG connections are as follows:
JTAG pin | ARM pin | Net description
3 4 TRST
5 2 TDI
7 3 TMS
9 5 TCK (10k pull down to gnd)
11 100 RTCK
13 1 TDO (10k pull up to 3.3V)
15 17 RST (10k pull up to 3.3V)
17, 19 10k pull down to gnd

I've tried with and without the pull up/down resistors mentioned above, and neither configuration helps. Those resistors are chosen based on keil schematics, and looking at what the LPC23XX user manual says about internal JTAG pull up/down resistors.

Thanks for your help,
Ben