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Home > Level Two Interface > Accessing RAMs using the AXI slave interface |
This section describes how to access the TCM and cache RAMs using the AXI slave interface.
Table 9.25 shows the bits of the ARCSELSm or AWCSELSm inputs, that determine the target of a transaction. Each signal is a one-hot 4-bit input, with each bit corresponding to a particular RAM or group of RAMs.
Table 9.25. RAM region decode
AxCSELSm bit | One-hot RAM select |
---|---|
[3] | Data cache RAMs |
[2] | Instruction cache RAMs |
[1] | B0TCM and B1TCM |
[0] | ATCM |
The remaining addressing information is encoded in ARADDRSm[22:0] for reads and AWADDRSm[22:0] for writes. The AXI-slave interface does not use the other bits of the address, ARADDRSm[31:23] and AWADDRSm[31:23], except for the purposes of bus-ECC. For more information see:
Because AWCSELSm and AWADDRSm are similar to ARCSELSm and ARADDRSm, the following sections describe their common features as AxCSELSm and AxADDRSm, noting any differences between them.