The following figure shows the Reorder, Refresh, and Power Savings Options tab of the HBM IP.
Figure 1. AXI HBM Customize IP – Reorder, Refresh, and Power Savings Options
Tab
Traffic Options
- Select Traffic Pattern
- Traffic pattern can be selected as Linear, Random, or User_Defined. For Linear and Random traffic pattern, the wizard configures the IP to provide optimum performance for the given traffic pattern. When User_Defined traffic pattern is selected, predefined configuration is not provided.
Reorder Options
Note: These options are only available if not using a custom address map.
- Enable Request Reordering
- This enables the controller to re-order commands within a 64 deep window to improve efficiency. This re-ordering is different than the re-ordering happens in the AXI3 interface based on the ID tag.
- Coherency in Reordering
- Permits the controller to re-order commands provided they are not in the same bank and row.
- Reorder Queue Age Limit
- Sets the maximum number of newer AXI commands that can be issued ahead of a pending AXI command. This allows for adjustment of maximum latency for any AXI command versus reordering for optimum memory throughput.
- Enable Close Page Reorder
- When enabled, this closes a page after an instruction has completed. When disabled, the page remains open until a higher priority operation is requested for another page in the same bank.
- Enable Lookahead Pre-Charge, Activate
- These are used to allow the controller to maximize throughput by optimizing commands in the 12-command queue. If these options are disabled, all commands are processed in the order received.
- Enable Lookahead Single Bank Refresh
- This allows the controller to insert refresh operations based on pending operations to maximize efficiency. This option isn't selectable until the "Single Bank Refresh" option is enabled.
- Minimum Period to issue Subsequent Single Bank Refresh
- Enter a value for the minimum period for a single bank refresh.
- Disable Dynamic Open Page
- When checked the Dynamic Open Page mode is disabled and a Pure Open Page Mode is enabled.
Refresh Options
- Single Bank Refresh
- Banks are refreshed individually. This affects bank access order to minimize the number of refreshes required.
- Enable Refresh Period Temperature Compensation
- The controller adjusts the rate of refreshes based on the temperature of the memory stacks.
- Hold Off Refresh for Read/Write
- This option allows a refresh to be delayed to permit operations to complete. Refreshes might need to be done more frequently to compensate for this delay.
Power Saving Options
- Idle Time to enter Self Refresh Mode
- After this number of idle cycles, the controller places all memory ranks in self-refresh. This feature is disabled when configured as '0'.
- Idle Time to enter Power Down Mode
- After this number of idle cycles, the controller places all memory ranks in power down mode. This feature is disabled when configured as '0'. The controller still generates refresh commands at the expected refresh interval.
- Enable Temperature Controlled Self-Refresh Intervals
- When in Self-Refresh, adjust the refresh rate as needed based on the memory temperature. This only applies when "Idle Time to enter Self Refresh Model" has non-zero value.