watchdog.t2t

== Watchdog timer ==[peri_timer_wdt]

The LS1024A features a 32 bit watchdog counter, which can reset the system if
the counter value is not reset before it reaches its programmable limit.

The watchdog timer is similar to the other low-order timers: it is a
free-running 32 bit counter, driven by the AHB clock (usually 250 MHz).

Unlike the regular timers, the watchdog counter is not reset when it reaches
the HIGH_BOUND value.

Also note that the watchdog only triggers a reset when the counter value is
equal to the HIGH_BOUND value; no reset will occur while the counter is above
HIGH_BOUND.

For the system to actually reset on watchdog timer overflow, the AXI_WD_RST_EN
bit must be set in the [DEVICE_RST_CNTRL #clkcore_regs_device_rst_cntrl]
register.

=== Registers ===[peri_timer_wdt_regs]

|| Symbol | Offset | Description ||
| [HIGH_BOUND #peri_timer_wdt_reg_high_bound] | 0xd0 | Watchdog max count register |
| [CONTROL #peri_timer_wdt_reg_control] | 0xd4 | Watchdog control register |
| [CURRENT_COUNT #peri_timer_wdt_reg_current_count] | 0xd8 | Watchdog current count register |

==== HIGH_BOUND (0x904500d0) ====[peri_timer_wdt_reg_high_bound]

Maximum value for the watchdog counter at which to perform a system reset.
Writing a new value resets CURRENT_COUNT.

|| Symbol | Bit range | R/W | Description ||
| HIGH_BOUND | 31-0 | RW | Maximum counter value |

==== CONTROL (0x904500d4) ====[peri_timer_wdt_reg_control]

Watchdog timer control register. Can enable or disable the watchdog timer.

Disabling the watchdog does not cause the watchdog timer to stop counting, but
only prevents it from requesting a system reset.

|| Symbol | Bit range | R/W | Description ||
| reserved | 31-1 | R | Reserved. Must be 0. |
| ENABLE | 0 | RW | Enable the watchdog reset timer. 0=disable 1=enable |

==== CURRENT_COUNT (0x904500d8) ====[peri_timer_wdt_reg_current_count]

Watchdog timer current count.

|| Symbol | Bit range | R/W | Description ||
| CURRENT_COUNT | 31-0 | RW | Read or set the current watchdog timer counter. |