AMBA AHB - Chap.2 AMBA Signals

2-1 AMBA signal names
prefixes...

2-2 AMBA AHB signal list

AMBA AHB signals

HCLK
HRESETn
HADDR [31:0]
HTRANS [1:0] - transfer type : NONSEQUENTIAL(10) / SEQUENTIAL(11) / IDLE(00) / BUSY(01)
HWRITE - 1: write / 0: read
HSIZE [2:0]
HBURST [2:0] - 4 / 8 / 16. wrapping / incrementing
HPROT [3:0]
HWDATA [31:0] - may easily extended to allow for higher bandwidth operation
HSELx - source : decoder
HRDATA [31:0]  - may easily extended to allow for higher bandwidth operation
HREADY
HRESP [1:0] - OKAY / ERROR / RETRY / SPLIT

Arbitration signals

HBUSREQx - source : master
HLOCKx - source : master
HGRANTx - source : arbiter
HMASTER [3:0] - source : arbiter, 1 amba system, maximum 16 masters
HMASTERLOCK - source : arbiter
HSPLITx [15:0] - source : SPLIT-capable slave

2-3 AMBA ASB signal list

2-4 AMBA APB signal list

PCLK
PRESETn
PADDR [31:0]
PSELx - source : seconary decoder (bridge)
PENABLE
    APB strobe - used to time all accesses on the peripheral bus
                       indicate the second cycle of an APB transfer
                       the rising dege of PENABLE occurs in the middle of the APB transfer
PWRITE - 1 : write / 0 : read

PRDATA - up to 32-bits wide
PWDATA - up to 32-bits wide