|
Hi all, My question is about HPI on C6713. Is it allowed to generate HSTROBE transitions only by HCS signal or not? we has conncet HDS1 and HDS2 pins to dont-care values and generate desired HSTROBE transitions by HCS only. but there is no any transition on HREADY pin. what is the problem?? Thank all in advance. |
|
|
HPI Problem
Started by ●October 27, 2004
Reply by ●October 28, 20042004-10-28
|
Jalal- > My question is about HPI on C6713. > Is it allowed to generate HSTROBE transitions only by HCS signal or > not? > > we has conncet HDS1 and HDS2 pins to dont-care values and generate > desired HSTROBE transitions by HCS only. but there is no any > transition on HREADY pin. what is the problem?? What are HDS1 and HDS2 connected to? HDS1 has internal pull-up so should not be connected. /HDS2 can be connected to /HCS. Also, other HPI start-up biggies: - /HAS should be unconnected (also has internal pull-up) -what is your /TRST value? MUST be low (use 10k pull-down) -what is your measured CLKOUT value, in MHz? You have to verify this -Jeff |
Reply by ●October 28, 20042004-10-28
|
I am not sure what you mean by "conncet HDS1 and HDS2 pins to dont-care
values" - if you tie one of them high and the other one low it should
work.
From TI's spru190d.pdf -
Used together, HCS, HDS1, and HDS2 generate
an active (low) internal HSTROBE signal. HSTROBE is active (low) only when both
HCS is active and either (but not both) HDS1 or HDS2 is active.
mikedunn jalal_habibi <j...@yahoo.com> wrote: Hi all, |
Reply by ●October 29, 20042004-10-29
|
Jalal- > we pull up HDS1 and pull down HDS2. HCS is connected to Host > Interface (USB controller: TUSB5052). HAS is not connected. > CLKOUT is 75 Mhz. Are these correct? Yes they sound Ok. Did you check /TRST signal? What is it connected to? Is /RESET de-asserted. If you have /RESET on, then "no HPI for you". Also, what about boot mode? How does the processor come up? It's easy enough to cause the onchip bootloader to do some crazy things, like try to boot from serial port or EMIF, if you're not careful. -Jeff |
Reply by ●October 30, 20042004-10-30
