Source code for hwtLib.amba.constants

"""
Constant used for a signals in AXI, AXI-lite interfaces.
"""
BURST_FIXED = 0b00
BURST_INCR = 0b01
BURST_WRAP = 0b10


[docs]def BYTES_IN_TRANS(n): n = int(n) return n.bit_length() - 1
# http://www.gstitt.ece.ufl.edu/courses/fall15/eel4720_5721/labs/refs/AXI4_specification.pdf p.65 # Normal Non-cacheable Bufferable CACHE_DEFAULT = 3 """ +--------------+--------------+-----------------------------------------+ | ARCACHE[3:0] | AWCACHE[3:0] | Memory type | +==============+==============+=========================================+ | 0000 | 0000 | Device Non-bufferable | | 0001 | 0001 | Device Bufferable | | 0010 | 0010 | Normal Non-cacheable Non-bufferable | | 0011 | 0011 | Normal Non-cacheable Bufferable | +--------------+--------------+-----------------------------------------+ | 1010 | 0110 | Write-through No-allocate | | 1110 (0110) | 0110 | Write-through Read-allocate | | 1010 | 1110 (1010) | Write-through Write-allocate | | 1110 | 1110 | Write-through Read and Write-allocate | +--------------+--------------+-----------------------------------------+ | 1011 | 0111 | Write-back No-allocate | | 1111 (0111) | 0111 | Write-back Read-allocate | | 1011 | 1111 (1011) | Write-back Write-allocate | | 1111 | 1111 | Write-back Read and Write-allocate | +--------------+--------------+-----------------------------------------+ """ PROT_DEFAULT = 0 """ :note: "prot" is an access permissions signals that can be used to protect against illegal transactions. +--------+-------+---------------------+ | PROT | Value | Function | +========+=======+=====================+ | [0] | 0 | Unprivileged access | | | 1 | Privileged access | | [1] | 0 | Secure access | | | 1 | Non-secure access | | [2] | 0 | Data access | | | 1 | Instruction access | +--------+----------+------------------+ """ QOS_DEFAULT = 0 LOCK_DEFAULT = 0 """ +-------+----------+-----------------------+ | RESP | Response | Desciption | +=======+==========+=======================+ | 0b00 | OKAY | Normal access success | | 0b10 | SLVERR | Slave error | | 0b11 | DECERR | Decode error | +-------+----------+-----------------------+ """ RESP_OKAY = 0 RESP_EXOKAY = 1 RESP_SLVERR = 2 RESP_DECERR = 3