block-ark

Block with all sorts of bus interfaces from duh-bus

Initializing the Workspace

requires wake 0.15 and wit 0.8.0

wit init workspace -a [email protected]:sifive/block-ark.git::wake -a [email protected]:sifive/environment-example-sifive.git
cd workspace
wake --init .

Generating Verilog

duh-export-scala block-ark/ark.full.json5 -o block-ark/src/
wake -v arkDUT Unit

Bus Interfaces

type	Initiator	Target	mem
AMBA4.AXI4-Lite	i2	t1	✓
AMBA4.AXI4	i4	t3	✓
AMBA4.AHBLite	i6	t5	✓
AMBA3.APB	i8	t7	✓
MEM.SPRAM	i10	t9	✓
MEM.DPRAM	i12	t11	✓
AMBA4.AXI4Stream	i14	t13
sifive.basic.channel	i16	t15
AMBA3.AXI			✓
TileLink			✓
Bundle

Walkthrough example import using duh

First ensure duh is installed and clone the block-ark repository

% git clone https://github.com/sifive/block-ark.git
% cd block-ark

Infer mappings to known bus definitions

Run duh-portinf to infer initial bus interface matches present in the ark design.

% duh-portinf -o ark-busprop.json ark.json5

The resulting ark-busprop.json file contains inferred bus interfaces present in the ark design:

"component": {
    "vendor": "sifive",
    "library": "blocks",
    "name": "ark",
    "version": "0.1.0",
    "busInterfaces": [
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_0-mapping_0-prefix_t3_axi4-slave-AXI4_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_1-mapping_0-prefix_i4_axi4-master-AXI4_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_2-mapping_0-prefix_i2_axi4lite-master-AXI4-Lite_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_3-mapping_0-prefix_t1_axi4lite-slave-AXI4-Lite_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_4-mapping_0-prefix_t5_ahblite_H-slave-AHBLite_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_5-mapping_0-prefix_i6_ahblite_H-master-AHB_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_6-mapping_0-prefix_i8_apb_P-master-APB4_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_7-mapping_0-prefix_t7_apb_P-slave-APB4_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_8-mapping_0-prefix_i12_dpram-master-DPRAM_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_9-mapping_0-prefix_t11_dpram-slave-DPRAM_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_10-mapping_0-prefix_i10_spram-master-SPRAM_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_11-mapping_0-prefix_t9_spram-slave-SPRAM_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_12-mapping_0-prefix_i14_stream_T-master-AXI4Stream_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_13-mapping_0-prefix_t13_stream_T-slave-AXI4Stream_rtl"},
        {"$ref": "#/definitions/busDefinitions/busint-portgroup_14-mapping_0-prefix_sys-slave-JTAG_rtl"}
    ],   
    "addressSpaces": []
}

Each entry in obj["component"]["busInterfaces"] is a JSON reference ($ref) to a dictionary defining a single bus interface for a select portgroup. The naming of these references follows the format:

busint-portgroup_{portgroup index}-mapping_{mapping index}-prefix_{portgroup prefix}-{master,slave}-{bus abstract name}

Ports within portgroup_0 share the prefix t3_axi4-slave and we can see from the reference name alone that the correct bus definition was inferred for this portgroup. We can further examine the mapping of physical ports within the portgroup to the bus definition logical names:

"busint-portgroup_0-mapping_0-prefix_t3_axi4-slave-AXI4_rtl": {
    "name": "t3_axi4",
    "interfaceMode": "slave",
    "busType": {
        "vendor": "amba.com",
        "library": "AMBA4",
        "name": "AXI4",
        "version": "r0p0_0"
    },
    "abstractionTypes": [
        {
            "viewRef": "RTLview",
            "portMaps": {
                "ARLOCK": "t3_axi4_ARLOCK",
                "BREADY": "t3_axi4_BREADY",
                "WVALID": "t3_axi4_WVALID",
                ...
                "AWREGION": "t3_axi4_AWREGION",
                "AWPROT": "t3_axi4_AWPROT",
                "AWCACHE": "t3_axi4_AWCACHE_0",
                "ARUSER": [
                    "t3_axi4_ARAPCMD"
                ],
                "AWUSER": [
                    "t3_axi4_AWAPCMD",
                    "t3_axi4_AWALLSTRB",
                    "t3_axi4_AWCOBUF"
                ]
            }
        }
    ]
}

Notice that four user signals t3_axi4_ARAPCMD, t3_axi4_AWAPCMD, t3_axi4_AWALLSTRB, and t3_axi4_AWCOBUF for this AXI4 bus interface are correctly mapped to user port groups "ARUSER" and "AWUSER".

Ports within portgroup_14 share the prefix sys, and they are unexpectedly mapped to the JTAG bus definition. Examining the mapping we can see that this portgroup does not map well to JTAG:

"busint-portgroup_14-mapping_0-prefix_sys-slave-JTAG_rtl": {
    "name": "sys",
    "interfaceMode": "slave",
    "busType": {
        "vendor": "sifive.com",
        "library": "TEST",
        "name": "JTAG",
        "version": "0.1.0"
    },
    "abstractionTypes": [
        {
            "viewRef": "RTLview",
            "portMaps": {
                "TDI": [
                    "sys_int0",
                    "sys_int1",
                    "sys_int2",
                    "sys_int3",
                    "sys_int4",
                    "sys_int5",
                    "sys_int6",
                    "sys_int7"
                ],
                "TCK": "sys_clock_enable",
                "TDO": "sys_power_status",
                "__UMAP__": [
                    "sys_power_enable"
                ]
            }
        }
    ]
}

Furthermore, mappings to alternate bus definitions (obj["component"]["busInterfaceAlts"]) for this portgroup are not correct either:

"busInterfaceAlts": [
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_0-mapping_1-prefix_t3_axi4-slave-ACE-Lite_rtl"},
    ...
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_14-mapping_1-prefix_sys-slave-AXI4Stream_rtl"},
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_14-mapping_2-prefix_sys-master-AXI4Stream_rtl"},
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_14-mapping_3-prefix_sys-slave-ATB_rtl"},
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_14-mapping_4-prefix_sys-master-ATB_rtl"}
]

We can create a user-edited copy of ark-busprop.json in which we remove the reference to the chosen JTAG mapping for portgroup_14:

% cp ark-busprop.json ark-busprop.edit.json
# remove incorrect bus mapping for portgroup_14
# and validate the edited file
% duh validate ark-busprop.edit.json

Group remaining ports into bundles

Next run duh-portbundler to structure the remaining ports that were not previously assigned to a bus interface into structured bundles.

% duh-portbundler -o ark-final.json ark-busprop.edit.json

The resulting ark-final.json file contains the previously inferred bus interfaces and an additional two structured bundles under obj["component"]["busInterfaces"]:

"busInterfaces": [
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_0-mapping_0-prefix_t3_axi4-slave-AXI4_rtl"},
    ...
    {"$ref": "#/definitions/busDefinitions/busint-portgroup_13-mapping_0-prefix_t13_stream_T-slave-AXI4Stream_rtl"},
    {"$ref": "#/definitions/bundleDefinitions/bundle-sys"},
    {"$ref": "#/definitions/bundleDefinitions/bundle-root"}
]

Ports with the shared prefix sys are grouped together in a single structured bundle:

"bundle-sys": {
    "name": "sys",
    "interfaceMode": null,
    "busType": "bundle",
    "abstractionTypes": [
        {
            "viewRef": "RTLview",
            "portMaps": {
                "int": [
                    "sys_int0",
                    "sys_int1",
                    "sys_int2",
                    "sys_int3",
                    "sys_int4",
                    "sys_int5",
                    "sys_int6",
                    "sys_int7"
                ],
                "power": {
                    "enable": "sys_power_enable",
                    "status": "sys_power_status"
                },
                "clock_enable": "sys_clock_enable"
            }
        }
    ]
}

sys_intX signals are also grouped together into a single vector.

The remaining clock and reset_n ports are grouped together in a separate "root" bundle:

"bundle-root": {
    "name": "root",
    "interfaceMode": null,
    "busType": "bundle",
    "abstractionTypes": [
        {
            "viewRef": "RTLview",
            "portMaps": {
                "clock": "clock",
                "reset_n": "reset_n"
            }
        }
    ]
}