nextpnr/himbaechel
Joris van Zwieten a652a752de himbaechel/xilinx: don't override driven ADDR*L15 on cascaded RAMB36E1
pack_bram unconditionally disconnected ADDRARDADDRL15/ADDRBWRADDRL15
on every RAMB36E1 and tied them to VCC. Tying high is correct for
non-cascaded modes, but in a depth-cascaded pair (RAM_EXTENSION_A/B =
LOWER/UPPER) these pins carry the address MSB that selects between
the two 32K halves, and the port multixform has already wired
ADDRARDADDR[15] onto them. Overriding that with VCC pinned both reads
and writes to the upper half: address bit 15 was simply ignored.

Keep the tie as a fallback for undriven pins only.

Hardware-verified on xc7a100t: a 128K ROM built from cascaded
RAMB36E1 pairs passes a full 32/32 content fingerprint check that
failed before this change.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-30 15:47:34 +02:00
..
himbaechel_dbgen himbaechel: Extend API to enable cell delay override (#1535) 2025-08-20 06:32:18 +02:00
uarch himbaechel/xilinx: don't override driven ADDR*L15 on cascaded RAMB36E1 2026-07-30 15:47:34 +02:00
.gitignore himbächel: Initial implementation 2023-05-13 08:26:41 +02:00
CMakeLists.txt himbaechel: Merge all test entrypoints into one 2026-07-27 11:01:32 +02:00
arch.cc himbaechel: Enable use of electrostatic placer (#1657) 2026-03-03 12:19:41 +01:00
arch.h himbaechel: bounds check getBelByLocation 2026-05-04 13:38:04 +02:00
arch_pybindings.cc himbaechel: Add Python binding for get_tile_wire_range 2025-06-25 18:37:17 +02:00
arch_pybindings.h himbächel: Initial implementation 2023-05-13 08:26:41 +02:00
archdefs.h Add GroupId related calls to Himbaechel API (#1399) 2024-12-05 13:59:33 +01:00
chipdb.h himbaechel: Extend API to enable cell delay override (#1535) 2025-08-20 06:32:18 +02:00
himbaechel_api.cc himbaechel: Enable use of electrostatic placer (#1657) 2026-03-03 12:19:41 +01:00
himbaechel_api.h himbaechel: Enable use of electrostatic placer (#1657) 2026-03-03 12:19:41 +01:00
himbaechel_constids.h himbächel: Initial implementation 2023-05-13 08:26:41 +02:00
himbaechel_gfxids.h Add GroupId related calls to Himbaechel API (#1399) 2024-12-05 13:59:33 +01:00
himbaechel_helpers.cc himbaechel: Add support for new constants API 2023-11-07 09:00:03 +01:00
himbaechel_helpers.h clangformat 2024-09-30 14:51:33 +02:00
main.cc himbaechel: add uarch specific options parsing (#1582) 2025-10-21 14:41:53 +02:00
test_main.cc himbaechel: Merge all test entrypoints into one 2026-07-27 11:01:32 +02:00