Bypassing the daisy chain

[sphinx]

This document looks very interesting. If the DCH boxes have an ATDI and/or TDISEL pin, then maybe we can read the flash.

"When the TDISEL pin held high and four consecutive IDCODE instructions are issued, LA-ispPAC-POWR1014/A responds by making its active JTAG data input the ATDI pin. When ATDI is selected, data on its TDI pin is ignored
until the JTAG state machine returns to the Test-Logic-Reset state. This method of selecting ATDI takes advantage of the fact that a JTAG device with an IDCODE register will automatically load its unique IDCODE instruction into the Instruction Register after a Test-Logic-Reset. This JTAG capability permits blind interrogation of devices so that their location in a serial chain can be identified without having to know anything about them in advance. A blind interrogation can be made using only the TMS and TCLK control pins, which means TDI and TDO are not required for performing the operation. Figure 5-28 illustrates the logic for selecting whether the TDI or ATDI pin is the active data input to LA-ispPAC-POWR1014/A."

"TDISEL pin enables switching between the ATDI and the standard JTAG signal TDI. When the internally pulled-up TDISEL = 1, standard TDI pin is enabled and when the TDISEL = 0, ATDI is enabled."

http://www.latticesemi.com/documents/DS1014.pdf