L-tile and H-tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide
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6.1.2.3. 32-Bit Control Register Access (CRA) Slave Signals
The CRA interface provides access to the control and status registers of the Avalon-MM bridge. This interface has the following properties:
- 32-bit data bus
- Supports a single transaction at a time
- Supports single-cycle transactions (no bursting)
| Signal Name |
Direction |
Description |
|---|---|---|
| cra_read_i |
Input |
Read enable. |
| cra_write_i |
Input |
Write request. |
| cra_address_i[14:0] |
Input |
|
| cra_writedata_i[31:0] |
Input |
Write data. The current version of the CRA slave interface is read-only. Including this signal as part of the Avalon-MM interface, makes future enhancements possible. |
| cra_readdata[31:0] |
Output |
Read data lines. |
| cra_byteenable_i[3:0] |
Input |
Byte enable. |
| cra_waitrequest_o |
Output |
Wait request to hold off additional requests. |
| cra_chipselect_i |
Input |
Chip select signal to this slave. |
| cra_irq_o |
Output |
Interrupt request. A port request for an Avalon-MM interrupt. |