There is no one way that the READY signals on a channel are supposed to behave. There are no requirements for when READY should be asserted or how long READY should remain asserted, nor any that states that the READY must be asserted following a power up.
The control of the READY signal is set in the DRIVER of the given AGENT. For masters these are:
- RREADY
- BREADY
For slaves these are:
- AWREADY
- ARREADY
- WREADY
To control the generation of the READY signal there are two main configurations; however, to simplify the programming model these might be presented as different configurations.
The following table shows the configurable READY delay description.
| Member Name | Default | Range | Description |
|---|---|---|---|
| use_variable_ranges | FALSE | 0..1 |
When set TRUE, this property instructs the ready_gen class to generate a random value for high_time, low_time, and event_count based on the minimum/maximum ranges. When set FALSE, the ready_gen uses the programmed value of the high_time, low_time, and event_count. |
| max_low_time | 5 | 0..2 32 - 1 | Used to constrain the low_time value. Indicates the maximum range of the low_time constraint. |
| min_low_time | 0 | 0..2 32 - 1 | Used to constrain the low_time value. Indicates the minimum range of the low_time constraint. |
| low_time | 2 | 0..2 32 - 1 | When used, indicates the number of cycles that *READY is driven Low. |
| max_high_time | 5 | 0..2 32 - 1 | Used to constrain the high_time value. Indicates the maximum range of the high_time constraint. |
| min_high_time | 0 | 0..2 32 - 1 | Used to constrain the high_time value. Indicates the minimum range of the high_time constraint. |
| high_time | 5 | 0..2 32 - 1 | When used, indicates the number of cycles that *READY is driven High. |
| max_event_count | 1 | 1..2 32 - 1 | Used to constrain the event_count value. Indicates the maximum range of the event_count constraint. |
| min_event_count | 1 | 1..2 32 - 1 | Used to constrain the event_count value. Indicates the minimum range of the event_count constraint. |
| event_count | 1 | 0..2 32 - 1 | When used, indicates the number of handshakes that are sampled before the end of the policy. |
| event_count_reset | 2000 | 0..2 32 - 1 | Watchdog wait time. |