ZHCSNX8B December 2020 – September 2023 TPS6593-Q1
PRODUCTION DATA
The watchdog includes a watchdog fail counter WD_FAIL_CNT[3:0] that increments because of bad events or decrements because of good events. Furthermore, the watchdog includes two configurable thresholds:
When the WD_FAIL_CNT[3:0] counter value is less than or equal to the configured Watchdog-Fail threshold (WD_FAIL_TH[2:0]) and bit WD_FIRST_OK=1, the MCU can set the ENABLE_DRV bit when no other error-flags are set.
When the WD_FAIL_CNT[3:0] counter value is greater than the configured Watchdog-Fail threshold (WD_FAIL_CNT[3:0] > WD_FAIL_TH[2:0]), the device clears the ENABLE_DRV bit, sets the error-flag WD_FAIL_INT, and pulls the nINT pin low.
When the WD_FAIL_CNT[3:0] counter value is greater than the configured Watchdog-Fail plus Watchdog-Reset threshold (WD_FAIL_CNT[3:0] > (WD_FAIL_TH[2:0] + WD_RST_TH[2:0])) and the watchdog-reset function is enabled (configuration bit WD_RST_EN=1), the device generates a WD_ERROR trigger in the state machine (see PFSM Trigger Selections) and sets the error-flag WD_RST_INT, and pulls the nINT pin low. Unless described otherwise in the user's guide of the orderable part number, this WD_ERROR trigger in the state machine causes the TPS6593-Q1 to execute a warm-reset, during which the nRSTOUT pin pulled low, and released after a pre-configured delay time.
The device clears the WD_FAIL_CNT[3:0] each time the watchdog enters the Long Window. The status bits WD_FAIL_INT and WD_RST_INT are latched until the MCU writes a ‘1’ to these bits.
Overview of Watchdog Fail Counter Value Ranges and Corresponding Device Status gives an overview of the Watchdog Fail Counter value ranges and the corresponding device status.
| Watchdog Fail Counter value WD_FAIL_CNT[3:0] | Device Status |
|---|---|
| WD_FAIL_CNT[3:0] ≤ WD_FAIL_TH[2:0] | MCU can set the ENABLE_DRV bit if WD_FIRST_OK=1 and no other error-flags are set. |
| WD_FAIL_TH[2:0] < WD_FAIL_CNT[3:0] ≤ (WD_FAIL_TH[2:0] + WD_RST_TH[2:0]) | The device sets error-flag WD_FAIL_INT and pulls the nINT pin low. Furthermore, , the device clears the ENABLE_DRV bit. |
| WD_FAIL_CNT[3:0] > (WD_FAIL_TH[2:0] + WD_RST_TH[2:0]) | If configuration bit WD_RST_EN=1, device generates WD_ERROR trigger in the state machine and reacts as defined in the PFSM, sets the error-flag WD_RST_INT, and pulls the nINT pin low. See Summary of Interrupt Signals for the interrupt handling of WD_RST. |
The WD_FAIL_CNT[3:0] counter responds as follows:
Refer to Watchdog Trigger Mode and Watchdog Q&A Related Definitions respectively for definitions of good events and bad events.