We're implementing programming support of Flash for device from subject. And
we're faced with some issue, see description below:
1. After power-on device we can read ID register via JTAG successfully.
2. Enter scan chain 2, which enables the Embedded ICE macrocell registers to be
accessed. Processor is forced into debug state by asserting the DBGRQ bit of
the debug control register in EmbeddedICE and monitor DBGACK in debug status
3. DBGACK is set and ARM7TDMI is in debug mode and halted.
4. In this point we select scan chain 1
After selecting scan chain 1 we receive no response from TAP controller. All
instructions shifted into TAP controller are ignored and TDO pin is permanently
high (we have pull-up on this pin).
Is the problem in power-up sequence?
Does this device need special settings of any pins, which are not described in
Thank you in advance.