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Fix EXI DO/DI swap: rename nets + swap damping resistors, no copper changes

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SP1 DO/DI naming is console-perspective (verified against SD Gecko and
SD2SP2 wiring): pin 6 DO = GC data out = adapter MOSI input, pin 9 DI =
GC data in = adapter MISO output. The design doc's SP1 table had the
roles reversed and the schematic followed it, putting the FPGA's MISO
driver on the GC-driven DO line (bus contention).

Fix keeps all PCB routing identical:
- Swap net names EXI_MOSI(_RAW) <-> EXI_MISO(_RAW) across exi/Fpga/root
  sheets and the PCB (also renames the D2 PUSB3AB6 channel assignments).
- Swap R21 (22R) <-> R25 (33R) identities between the two footprint
  positions so 33R stays on the FPGA-driven MISO line, 22R on the MOSI
  input.
- Correct the SP1 pin table + MISO-tristate note in
  docs/gc_bba_fpga_design.md (root cause).

Resulting board pin map (for the future board PCF): EXI_MOSI = FPGA
pin 4 (IOB_8a, input), EXI_MISO = pin 3 (IOB_9b, output).

Verified: ERC 0, DRC 0 errors with schematic parity 0, netlist shows
J3.6(DO)->R21->pin 4 and J3.9(DI)->R25->pin 3.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Dennis Brentjes
2026-07-18 12:36:41 +00:00
parent 4704dfbb36
commit fe96876a80
7 changed files with 94 additions and 86 deletions
Download Patch File Download Diff File Expand all files Collapse all files
hardware/re-bba-rb/exi.kicad_sch
+12 -12
View File
@@ -1423,7 +1423,7 @@
)
(uuid "fd73b349-d700-4bfa-9b20-b662f3b5fa69")
)
(label "EXI_MISO_RAW"
(label "EXI_MOSI_RAW"
(at 27.94 90.17 180)
(effects
(font
@@ -1433,7 +1433,7 @@
)
(uuid "1673f89a-b196-4e3a-8b31-50ae5115685e")
)
(label "EXI_MOSI_RAW"
(label "EXI_MISO_RAW"
(at 27.94 85.09 180)
(effects
(font
@@ -1463,7 +1463,7 @@
)
(uuid "463748b5-0fc0-4757-8342-6383f5a7930f")
)
(label "EXI_MISO_RAW"
(label "EXI_MOSI_RAW"
(at 64.77 88.9 0)
(effects
(font
@@ -1493,7 +1493,7 @@
)
(uuid "70f96782-2886-4b5b-94ad-95906cdd520c")
)
(label "EXI_MOSI_RAW"
(label "EXI_MISO_RAW"
(at 64.77 96.52 0)
(effects
(font
@@ -1586,7 +1586,7 @@
)
(uuid "a7933167-c81c-41fc-a28b-3d624d2c6c3c")
)
(hierarchical_label "EXI_MISO"
(hierarchical_label "EXI_MOSI"
(shape bidirectional)
(at 74.93 88.9 0)
(effects
@@ -1608,7 +1608,7 @@
)
(uuid "d8101c24-4fbe-49d0-a9c8-3adfc57b1ed6")
)
(hierarchical_label "EXI_MOSI"
(hierarchical_label "EXI_MISO"
(shape bidirectional)
(at 74.93 96.52 0)
(effects
@@ -2056,7 +2056,7 @@
(dnp no)
(fields_autoplaced yes)
(uuid "329d834f-89a5-4c24-9ac5-f7fd739521d7")
(property "Reference" "R25"
(property "Reference" "R21"
(at 68.58 82.55 90)
(show_name no)
(do_not_autoplace no)
@@ -2066,7 +2066,7 @@
)
)
)
(property "Value" "33"
(property "Value" "22"
(at 68.58 85.09 90)
(show_name no)
(do_not_autoplace no)
@@ -2151,7 +2151,7 @@
(instances
(project "re-bba-rb"
(path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/1b071f68-b4ea-469c-942f-de06380c9077"
(reference "R25")
(reference "R21")
(unit 1)
)
)
@@ -2631,7 +2631,7 @@
(dnp no)
(fields_autoplaced yes)
(uuid "8bc64cda-903a-4cfc-b2c8-033616a6f51f")
(property "Reference" "R21"
(property "Reference" "R25"
(at 68.58 90.17 90)
(show_name no)
(do_not_autoplace no)
@@ -2641,7 +2641,7 @@
)
)
)
(property "Value" "22"
(property "Value" "33"
(at 68.58 92.71 90)
(show_name no)
(do_not_autoplace no)
@@ -2726,7 +2726,7 @@
(instances
(project "re-bba-rb"
(path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/1b071f68-b4ea-469c-942f-de06380c9077"
(reference "R21")
(reference "R25")
(unit 1)
)
)