This commit contains a rewrite of the jtagspi protocol and covers both
changes in the jtagspi.c openocd driver and the bscan_spi
(xilinx_bscan_spi) proxy bitstreams. The changes are as follows:
1. Always perform IR scan to ensure proper clearing of BYPASSed DRs.
2. Insert alignment cycles for all BYPASSed TAPs:
The previous logic was erroneous. The delay in clock cyles from a bit
written to the jtag interface to a bit read by the jtag interface is:
* The number of BYPASSed TAPs before this (jtagspi) tap
* The length of the jtagspi data register (1)
* The number of BYPASSed TAPs before this one.
I.e. it is just the number of enabled TAPs. This also gets rid of the
configuration parameter DR_LENGTH.
3. Use marker bit to start spi transfer
If there are TAPs ahead of this one on the JTAG chain, and we are in
DR-SHIFT, there will be old bits toggled through first before the first
valid bit destined for the flash.
This delays the begin of the JTAGSPI transaction until the first high bit.
4. New jtagspi protocol
A JTAGSPI transfer now consists of:
* an arbitrary number of 0 bits (from BYPASS registers in front of the
JTAG2SPI DR)
* a marker bit (1) indicating the start of the JTAG2SPI transaction
* 32 bits (big endian) describing the length of the SPI transaction
* a number of SPI clock cycles (corresponding to 3.) with CS_N asserted
* an arbitrary number of cycles (to shift MISO/TDO data through
subsequent BYPASS registers)
5. xilinx_bscan_spi: clean up, add ultrascale
This is tested on the following configurations:
* KC705: XC7K325T
* Sayma AMC: XCKU040
* Sayma AMC + RTM): XCKU040 + XC7A15T, a board with integrated FTDI JTAG
adapter, SCANSTA JTAG router, a Xilinx Ultrascale XCKU040 and a Xilinx
Artix 7 15T. https://github.com/m-labs/sinara/wiki/Sayma
* Custom board with Lattice FPGA + XC7A35T
* CUstom board with 3x XCKU115-2FLVA1517E
Change-Id: I7361e9fb284ebb916302941735eebef3612aa103
Signed-off-by: Robert Jordens <jordens@gmail.com>
Reviewed-on: http://openocd.zylin.com/4236
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
* port to new migen
* streamline package/part specification
* add pullup (Series3, Series6) and pullnone (Series7) for unused pins
as xilinx impact/vivado do it.
* specify respective toolchains
* build Series7 with vivado (broader support, faster)
* point to prebuilt bitstreams at https://github.com/jordens/bscan_spi_bitstreams
Change-Id: Ibfef3d78f855b754425f3e6131e2e49fa111e09a
Signed-off-by: Robert Jordens <jordens@gmail.com>
Reviewed-on: http://openocd.zylin.com/3173
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins
Reviewed-by: Robert Jördens
Reviewed-by: William D. Jones
Reviewed-by: Tim "mithro" Ansell <mithro@mithis.com>
Many FPGA board speak JTAG and have a SPI flash for their bitstream
attached to them. The SPI flash is programmed by first uploading a
proxy bitstream to the FPGA that connects the JTAG interface to the
SPI interface if the IR contains a certain USER instruction. Then the
SPI flash can be erase, written, read directly through the JTAG DR.
The JTAG and SPI signaling is compatible. Such a proxy bitstream only
needs to connect TDO-MISO, TDI-MOSI, TCK-CLK, and the activate the
chip select when the IR contains the special instruction and the JTAG
state machine is in the DR-SHIFT state.
Change-Id: Ibc21d793a83b36fa37e2704966aa5c837c4dd0d2
Signed-off-by: Robert Jordens <jordens@gmail.com>
Reviewed-on: http://openocd.zylin.com/2844
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
Robert Jordens