The AHB-Lite master port supports AHB in AMBA v2.0.
HPROT[3:0] is provided as an external port and is programmed from the Prot field in the CSW register with the following conditions:
HPROT[3:0] programming is supported.
Exclusive access is not supported, so HRESP is not supported.
See AHB-AP Control/Status Word Register, CSW, 0x00 for values of the Prot field.
HRESP is the only RESPONSE signal required by the AHB-AP:
AHB-Lite devices do not support SPLIT and RETRY and so HRESP is not required.
HRESP is not supported in the AHB-AP.
The AHB-AP cannot initiate a new AHB transfer every clock cycle (unpacked) because of the additional cycles required to serial scan in the new address or data value through a debug port. The AHB-AP supports two HTRANS transfer types, IDLE and NONSEQ.
When a transfer is in progress, it is of type NONSEQ.
When no transfer is in progress and the AHB-AP is still granted the bus then the transfer is of type IDLE.
The only unpacked HBURST encoding supported is SINGLE. Packed 8-bit transfers or 16-bit transfers are treated as individual NONSEQ, SINGLE transfers at the AHB-Lite interface. This ensures that there are no issues with boundary wrapping, to avoid additional AHB-AP complexity.