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author | Keith Rothman <537074+litghost@users.noreply.github.com> | 2021-04-05 13:47:15 -0700 |
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committer | Keith Rothman <537074+litghost@users.noreply.github.com> | 2021-04-05 14:00:26 -0700 |
commit | 32c03693c0cd683ef26d16d3051ec8a4031831e6 (patch) | |
tree | e832842dad49e60eb41eb56dce41b92d2e03d8f7 /docs | |
parent | 433d710c680dd4c2f178cf8c11880247ea868e7d (diff) | |
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Iterate DeviceResources doc with feedback from review.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
Diffstat (limited to 'docs')
-rw-r--r-- | docs/device_resources.md | 137 |
1 files changed, 134 insertions, 3 deletions
diff --git a/docs/device_resources.md b/docs/device_resources.md index 9770440..1d8efec 100644 --- a/docs/device_resources.md +++ b/docs/device_resources.md @@ -89,14 +89,145 @@ end at an input/inout BEL pin. If a net enters a site, that net **must** end at an input/inout BEL pin. It is not legal for a net to enter and leave a site. If such a path is required, a pseudo PIP should be added to the schema. +## Site example + +The following is an example site for a SLICE for a non-existant device. + +``` + ▲ + CO│ │ + ┌──────────────────────────┼─────────────────────────────────────┼──────┐ + │ │ │ │ + B0│ I0┌───────┐ │ BLUT ┌───────┐ ▼ CLK │ +─────┼────►│ │ ┌────────o─────────────────┬────►│ │ ┌────┐ │ + B1│ I1│ │O │ │ │XOR │ │D D│ │Q │ FFOUT +─────┼────►│ BLUT3 ├───┤ │ ┌────────┬──o────►│ FFMUX ├──►│ FF ├───┼───► + B2│ I2│ │ │ │ │ │ |ALUT │ │ │ │ │ +─────┼────►│ │ │ │ │ ┌──┬──o──o────►│ │ └────┘ │ + │ └───────┘ │ ┌───┴───┐ │ │ │ │ │ └───────┘ │ + │ │ SI│ │ │ │ │ │ │ │ + │ └───►│ ├─┘ │ │ │ │ │ + │ DX│ CARRY │ O │ │ │ │ │ + │ ┌───►│ │ │ │ │ │ │ + A0│ I0┌───────┐ │ └───┬───┘ │ │ │ │ ┌────────┐ │ +─────┼────►│ │ │ │ │ │ │ │ BLUT │ │ │ + A1│ I1│ │O │ │ │ │ │ └─────►│ │OUT │ OUT +─────┼────►│ ALUT3 ├───┴────────o────────┘ │ │ XOR │ OUTMUX ├──────────┼────► + B2│ I2│ │ │ │ └────────►│ │ │ +─────┼────►│ │ │ │ ALUT │ │ │ + │ └───────┘ │ └───────────►└────────┘ │ + │ │ │ + │ │ │ + └──────────────────────────┼────────────────────────────────────────────┘ + CI│ + │ +``` + +In the above example, there 17 BELs: + +| BEL Name | Category | # Input | # Output | +|----------|-----------|---------|----------| +| ALUT3 | Logic | 3 | 1 | +| BLUT3 | Logic | 3 | 1 | +| CARRY | Logic | 3 | 2 | +| FF | Logic | 2 | 1 | +| FFMUX | Routing | 3 | 1 | +| OUTMUX | Routing | 3 | 1 | +| A0 | Site port | 0 | 1 | +| A1 | Site port | 0 | 1 | +| A2 | Site port | 0 | 1 | +| B0 | Site port | 0 | 1 | +| B1 | Site port | 0 | 1 | +| B2 | Site port | 0 | 1 | +| CI | Site port | 0 | 1 | +| CLK | Site port | 0 | 1 | +| CO | Site port | 1 | 0 | +| FFOUT | Site port | 1 | 0 | +| OUT | Site port | 1 | 0 | + +Each site port BEL has a site pin, so the site pins are: + +| Site Pin Name | Direction | +|---------------|-----------| +| A0 | In | +| A1 | In | +| A2 | In | +| B0 | In | +| B1 | In | +| B2 | In | +| CI | In | +| CLK | In | +| CO | Out | +| FFOUT | Out | +| OUT | Out | + +The BEL BLUT3 has 4 BEL pins: + +| BEL pin name | Direction | +|--------------|-----------| +| I0 | In | +| I1 | In | +| I2 | In | +| O | Out | + +The BEL A0 has 1 BEL pin: + +| BEL pin name | Direction | +|--------------|-----------| +| A0 | Out | + +The BEL OUTMUX has 4 BEL pins: + +| BEL pin name | Direction | +|--------------|-----------| +| BLUT | In | +| XOR | In | +| ALUT | In | +| OUT | Out | + + +There are 12 site PIPs: + +| BEL name | In pin | Out pin | +|----------|--------|---------| +| BLUT3 | I0 | O | +| BLUT3 | I1 | O | +| BLUT3 | I2 | O | +| ALUT3 | I0 | O | +| ALUT3 | I1 | O | +| ALUT3 | I2 | O | +| FFMUX | ALUT | D | +| FFMUX | XOR | D | +| FFMUX | BLUT | D | +| OUTMUX | ALUT | OUT | +| OUTMUX | XOR | OUT | +| OUTMUX | BLUT | OUT | + + +The site wire BLUT3\_O has 4 BEL pins: + +| BEL Name | Pin | +|----------|------| +| BLUT3 | O | +| CARRY | SI | +| FFMUX | BLUT | +| OUTMUX | BLUT | + +The site wire B0 has 2 BEL pins: + +| BEL Name | Pin | +|----------|-----| +| B0 | B0 | +| BLUT3 | I0 | + ## Details ### Net routing summary Each net start at the driver output/inout BEL pin. The BEL pin will be connected to exactly 1 site wire. If the net sink can be reached within the -site, then the net can use site PIPs (through a routing BEL) to reach a site -wire connected to the input/inout BEL pin. +site, then the net can use site PIPs to reach a site wire connected to the +input/inout BEL pin. If the net sink is in another site, then the net must first reach a site port input BEL pin using site PIPs to reach the site wire connected to the site @@ -162,7 +293,7 @@ of the alternative site types can be used at a time for a particular site. A routing BEL represents statically configurable site routing by connecting a site wire connected to one of the input BEL pins to the output BEL pin of -the BEL. Routing BELs may only have 1 output BEL pin. +the BEL. Routing BELs must have 1 output BEL pin. #### Inverting routing BELs |