apb_target_timer

Files
file	apb_target_timer.cdl
	Simple timer target for an APB bus.

Detailed Description

Modules

module apb_target_timer::apb_target_timer	(	clock	clk,
		input bit	reset_n,
		input t_apb_request	apb_request,
		output t_apb_response	apb_response,
		output bit	timer_equalled[3]
	)

Simple timer with an APB interface. This is a monotonically increasing 31-bit timer with three 31-bit comparators.

The timers are read/written through the APB interface with the timer value read-only at address 0.

The three comparators are at addresses 4, 5 and 6. When a comparator is written it writes the 31-bit comparator value and it clears the timer's equalled bit. When a comparator is read it returns the comparator value (in bits [31;0]), and it returns the equalled status in bit [31] - while atomically clearing it.

Parameters

[in]	clk	System clock
[in]	reset_n	Active low reset
[in]	apb_request	APB request
[out]	apb_response	APB response
[out]	timer_equalled	One output bit per timer, mirroring the three timer's equalled state