Regarding XK-1A I have some queries as following below.
1) In XK-1A schematic no power on reset chip found. The chip reset pin RST_N is connected to JTAG –IN connector. That means the chip will be reset by XTAG-2.
My question:
After flashing binary when the board is powered on (stand alone) with out XTAG-2 then how power on reset is done properly?
2) In XK-1A board two x-links are used. Link-C connected with JTAG-IN terminal & Link-D is connected with JTAG-OUT terminal. That means when multiple boards are connected via x-link then slave board will be booted through x-link C as it is connected with JTAG-IN terminal.
My question:
As per documentation XMOS L1 chip can boot through x-link B not link C. Then how XK-1A boots over xlink. On another point MODE PIN 3&2 both are connected together and pulled UP. So the boot sequence can be set 0,0 & 1,1. Then in case of multiple board how slave boards boot sequence are set to boot over xlink.
regards
jags
Some confusions regarding XK-1A board
1) The RC network formed by R5 and C22 pulls TRST_N high after some delay.
2) You cannot boot an XK-1A via xlink, not directly that is: you can only directly
boot it from SPI or via JTAG, as you found out. The code you boot that way can
of course listen for a new boot image on whatever xlinks it wants: the limitation
that you can only boot over external link B (or the internal links) is a limitation of
the boot ROM code, not of the hardware.
2) You cannot boot an XK-1A via xlink, not directly that is: you can only directly
boot it from SPI or via JTAG, as you found out. The code you boot that way can
of course listen for a new boot image on whatever xlinks it wants: the limitation
that you can only boot over external link B (or the internal links) is a limitation of
the boot ROM code, not of the hardware.
segher,
Thanks for your reply.
1) As reset is done by RC network on XK1A board, then in my new L1 86 pins board, Can I use same RC network for reset instead a reset controller?
2) I put a ticket to XMOS support regarding booting over xlinks of XK-1A board. They are claiming that due to custom boot loader burnt on OTP XK-1A board boots over xlink-C instead link-B (default).
jags
Thanks for your reply.
1) As reset is done by RC network on XK1A board, then in my new L1 86 pins board, Can I use same RC network for reset instead a reset controller?
2) I put a ticket to XMOS support regarding booting over xlinks of XK-1A board. They are claiming that due to custom boot loader burnt on OTP XK-1A board boots over xlink-C instead link-B (default).
jags
1) Yes. It is much easier to get a proper reset controller working
reliably though.
2) Interesting. How should you set the MODE pins to make this
work? I guess I can peek at the code in OTP, I never knew there
was any :-)
reliably though.
2) Interesting. How should you set the MODE pins to make this
work? I guess I can peek at the code in OTP, I never knew there
was any :-)