Visible to Intel only — GUID: emt1671126711552
Ixiasoft
Visible to Intel only — GUID: emt1671126711552
Ixiasoft
13.1.1. HPS_COLD_nRESET Pin Function
You can assign HPS_COLD_nRESET to an available SDM I/O pin. This pin serves both as an input to reset the HPS and as an output to the external system to indicate that the HPS is in reset. Do not connect HPS_COLD_nRESET to the external flash. The SDM controls the reset of the external flash separately. You can configure this pin using the Intel® Quartus® Prime Pro Edition, under Device and Pin options > Configuration > Configuration pin option.
After Power-On-Reset and the SDM has loaded the bitstream, the HPS_COLD_nRESET signal becomes an output and asserts (low), and remains asserted, until User Mode is entered. Then, during User Mode, it becomes an input and is de-asserted (high) through an internal weak pullup resistor and allows the external system to drive this pin asserted when cold reset of the HPS is needed. This behavior is applicable for both Active Serial (AS) and Avalon-ST (AVST) configuration schemes.
The following table describes how the HPS_COLD_nRESET pin behaves during various stages of boot and configuration.
HPS_COLD_nRESET pin behavior | |||||||
---|---|---|---|---|---|---|---|
During USER MODE | HPS Cold Reset Trigger has occurred | Back in USER MODE | |||||
During HPS Reset | After HPS Reset | After HPS BOOT | |||||
HPS Cold Reset Trigger | Pin | (input) HIGH, user triggers LOW21 | (input) user controlled | (input) user sets HIGH | (output) HIGH | (input) HIGH | |
HPS (Mailbox Command or Watchdog Timeout)22 |
(input) HIGH, Watchdog Timeout or user sends mailbox command | (output) LOW | (output) LOW | (output) HIGH | (input) HIGH | ||
nCONFIG | (input) HIGH, user triggers nCONFIG | (output) LOW | (output) LOW. (output) HIGH when nCONFIG goes HIGH and nSTATUS goes HIGH |
(output) HIGH | (input) HIGH |