Bonfire Core together with I and D Cache. Designed to work with Xilinx Vivado IP Integrator.
| Name | Description | Acc | Address Range |
|---|---|---|---|
| BRAM_A | BRAM Port A (Data Port) | RW | 0xC0000000-0xCFFFFFFF |
| BRAM_B | BRAM Port B (Instruction Port) | RX | 0xC0000000-0xCFFFFFFF |
| M_AXI_IC | AXI4 Instruction Cache Master* | RX | 0x00000000-0xBFFFFFFF |
| M_AXI_DC | AXI4 Data Cache Master | RW | 0x00000000-0x3FFFFFFF |
| M_AXI_DP | AXI4Lite Data Port | RW | 0x80000000-0xBFFFFFFF |
| WB_DB | Wishbone Data Port | RW | 0x40000000-0x7FFFFFFF |
| clk_i | CPU clock | ||
| rst_i | CPU Reset (active high) | ||
| ext_irg_i | RISC-V External Interrupt | ||
| lirq0_i - lirq6_i | Local Interrupts 0-6 |
* All instruction fetches, expect in the BRAM Address Range are routed over the instruction cache and the M_AXI_IC Port. Trying to execute code e.g. on peripheral address ranges is therefore not possible. So most likely they are "mirrored" into DRAM mapped to address 0x0000000.
Remark: The Module has some more parameters than the ones documented here. The undocumented ones should not be changed from their default values and may be removed or replaced in the near future
| Name | Description | Values (Default in Bold) |
|---|---|---|
| CACHE_SIZE_WORDS | Instruction Cache Size in 32Bit Words | 2048 |
| CACHE_LINE_SIZE_WORDS | Instruiction Cache Line Size in 32 Bit Words | 8 |
| USE_DCACHE | Enable Data Cache | true false |
| DCACHE_MASTER_WIDTH | Width of M_AXI_DP data port | (32-128) (dvidable by 8!) |
| DCACHE_SIZE | Data Cache Size (Width is DCACHE_MASTER_WIDTH) | 2048 |
| DCACHE_LINE_SIZE | Data Cache Line Size (Width is DCACHE_MASTER_WIDTH) | 8 |
| ENABLE_TIMER | Enable mtime and mtimecmp | true false |
| REG_RAM_STYLE | Implement CPU register file as BRAM or distributed RAM | block distributed |
Restrictions:
- All parameters regarding memory size (cache and line sizes) must be powers of two.
- DCACHE_MASTER_WIDTH must be dividable by 8 and at least 32 Bit
- Switching off the Data Cache is currently not tested
- REG_RAM_STYLE is a string directly passed to the register file as attribute. Refer to Xilinx documentation for RAM inference on restritions.
All the restrictions are not explicitly checked and enforced by the code. So expect erratic behavior or at least inefficient implementations when violating this rules.