Xcore-Analog Boot - XMOS xCORE-Analog sliceKIT Hardware Manual

xCORE-Analog sliceKIT Hardware Manual
TCK
TMS
TDI
TDO
Figure 3:
JTAG Chain
The use of xSCOPE is covered in the xCONNECT Links section - see Section §2.6.
The xSCOPE xCONNECT link can be either enabled or disabled via a switch on the
XSYS adapter board.

2.5 xCORE-Analog boot

Master Core Boards boot from SPI flash, while slave Core Boards boot from xCON-
NECT link XLB from the next connected Core Board.
To allow re-use of the SPI boot pins (ports 1A, 1B, 1C, 1D) as signal I/O pins for the
Star , Triangle and A slot, a latched bus switch is used which connects the xCORE
SPI pins to either the SPI Flash or to the Slice Card Slots. The switch is controlled
by X0D42 and X0D43 (P8D6 and P8D7 on Tile 0: on the Triangle slot). Once the
device has booted X0D43 is used to enable or disable the SPI interface, X0D42
should then transition from low to high to latch the selection. The SPI selection
state is then maintained until the system is reset.
Once this sequence is completed the selection has been latched, therefore X0D42
and X0D43 return to performing their normal functions in the Triangle slot.
If the SPI is not disabled, then Slice Cards in the Star , Triangle or A slots may
not function as expected. If there are no Slice Cards in the Star , Triangle or A
slot, then it does not matter whether the SPI has been disabled or not. Therefore,
applications which require runtime access to the SPI flash should either leave the
Star , Triangle and A slots unpopulated or check to ensure that the Card which is
in there will be unaffected by the operation of the Flash.
The xTAG debug system can use the boot mode select signal to force all devices in
the chain (master and slave Core Boards) to boot from JTAG (don't boot) for debug
purposes.
XM005221A
0
TCK
TMS
TDI
1
CHAIN
SQUARE
A16
TDO
1
0
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