From 530f41cf7a5a11f5800f68e555ecb147218f903e Mon Sep 17 00:00:00 2001 From: Dennis Brentjes Date: Sat, 18 Jul 2026 12:51:54 +0000 Subject: [PATCH] Add FT2232H EEPROM interface resistors per datasheet Table 3.4 The 93LC46B's DO and DI were both tied directly to EEDATA, causing drive contention during EEPROM read turnaround. Per the FT2232H datasheet ("Connect directly to Data-In of the EEPROM and to Data-Out of the EEPROM via a 2.2K resistor. Also, pull Data-Out of the EEPROM to VCC via a 10K resistor"): - U7.4 (DO) moved onto new net EE_DO - R30 2.2k (UNI-ROYAL 0402WGF2201TCE, LCSC C25879, Basic) between EE_DO and EE_DATA - R31 10k (0402WGF1002TCE, C25744) pull-up from EE_DO to 3V3 - EEDATA -> DI (U7.3) stays direct Schematic only; R30/R31 still need placing near U7 in the PCB rework. Verified: ERC 0, EE_DATA = {U8.61, U7.3, R30.2}, EE_DO = {U7.4, R30.1, R31.2}, R31.1 on global /Power/3V3 (no orphan local net), netlist 115 vs BOM 114 differing only by the deliberate J3 exclusion. Co-Authored-By: Claude Fable 5 --- hardware/re-bba-rb/TODO.md | 12 +- hardware/re-bba-rb/Usb Connector.kicad_sch | 343 ++++++++++++++++++++- 2 files changed, 350 insertions(+), 5 deletions(-) diff --git a/hardware/re-bba-rb/TODO.md b/hardware/re-bba-rb/TODO.md index e166a96..148d53e 100644 --- a/hardware/re-bba-rb/TODO.md +++ b/hardware/re-bba-rb/TODO.md @@ -42,10 +42,14 @@ W5100S reference schematic, and JLCPCB manufacturing limits. ERC/DRC: clean. - [ ] Reconsider D4/D5 (USBLC6 on the line side of the magnetics): unusual — transformer already isolates; their VBUS pins float so they only clamp to GND. Remove or justify. -- [ ] **FT2232H EEPROM interface** (`Usb Connector.kicad_sch`): datasheet - Table 3.4 requires EEDATA → 93LC46B **DO via 2.2 kΩ** plus **10 kΩ - pull-up on DO to VCC** (DI stays direct). Board ties DO and DI both - directly to EE_DATA → read contention, unreliable EEPROM enumeration. +- [ ] **FT2232H EEPROM interface** (`Usb Connector.kicad_sch`) — schematic + part DONE 2026-07-17 per datasheet Table 3.4: U7.4 (DO) moved to new + net EE_DO; R30 (2.2 kΩ, C25879) inserted EE_DO→EE_DATA; R31 (10 kΩ, + C25744) pull-up EE_DO→3V3. EEDATA→DI stays direct. ERC 0, netlist + verified, BOM fields populated. Remaining (PCB rework): + - [ ] Place/route R30 + R31 near U7 (Update PCB from Schematic pulls + them in together with the 6 MDI termination parts — 8 new + footprints total). ## Functional / robustness diff --git a/hardware/re-bba-rb/Usb Connector.kicad_sch b/hardware/re-bba-rb/Usb Connector.kicad_sch index 9438b9a..3ff41a1 100644 --- a/hardware/re-bba-rb/Usb Connector.kicad_sch +++ b/hardware/re-bba-rb/Usb Connector.kicad_sch @@ -5692,7 +5692,7 @@ ) (uuid "ac105397-d5dc-45f9-9806-a0e2c2bae52f") ) - (label "EE_DATA" + (label "EE_DO" (at 246.38 224.79 0) (effects (font @@ -13158,4 +13158,345 @@ (page "1") ) ) + (text "FT2232H EEPROM iface (DS Table 3.4):\nEEDATA direct to DI; DO via 2.2k to EEDATA;\nDO pulled to VCC via 10k." + (exclude_from_sim no) + (at 250.19 228.6 0) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + (uuid "fbbeb5d7-ea1e-49e2-a1b0-560739897439") + ) + (symbol + (lib_id "Device:R") + (at 252.73 237.49 0) + (unit 1) + (body_style 1) + (exclude_from_sim no) + (in_bom yes) + (on_board yes) + (in_pos_files yes) + (dnp no) + (uuid "708b2cc6-9cab-421a-aa5f-8438af7af425") + (property "Reference" "R30" + (at 254.762 235.585 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Value" "2.2k" + (at 254.762 238.125 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Footprint" "Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder" + (at 252.73 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Datasheet" "" + (at 252.73 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Description" "Resistor" + (at 252.73 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "MPN" "0402WGF2201TCE" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Manufacturer" "UNI-ROYAL" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "LCSC" "C25879" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Tolerance" "1%" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (pin "1" + (uuid "866cbeda-82c6-4a9f-b413-114860d724cd") + ) + (pin "2" + (uuid "8802b213-6194-4847-a060-4001f66a2857") + ) + (instances + (project "re-bba-rb" + (path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/64033f5d-a512-44d7-9483-4c31ef84bd56" + (reference "R30") + (unit 1) + ) + ) + ) + ) + (symbol + (lib_id "Device:R") + (at 257.81 237.49 0) + (unit 1) + (body_style 1) + (exclude_from_sim no) + (in_bom yes) + (on_board yes) + (in_pos_files yes) + (dnp no) + (uuid "d084730f-d3f4-46df-85a6-eb2fc50a04d3") + (property "Reference" "R31" + (at 259.842 235.585 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Value" "10k" + (at 259.842 238.125 0) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + (justify left) + ) + ) + (property "Footprint" "Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder" + (at 257.81 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Datasheet" "" + (at 257.81 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Description" "Resistor" + (at 257.81 237.49 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "MPN" "0402WGF1002TCE" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Manufacturer" "UNI-ROYAL" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "LCSC" "C25744" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (property "Tolerance" "1%" + (at 0 0 0) + (hide yes) + (show_name no) + (do_not_autoplace no) + (effects + (font + (size 1.27 1.27) + ) + ) + ) + (pin "1" + (uuid "3c2b139d-0e30-469b-a9cb-620f8f545212") + ) + (pin "2" + (uuid "ad725537-f4f8-4c04-b6fb-9c6e03239785") + ) + (instances + (project "re-bba-rb" + (path "/dbb182a6-d579-468e-b98b-6f0950da9e3a/64033f5d-a512-44d7-9483-4c31ef84bd56" + (reference "R31") + (unit 1) + ) + ) + ) + ) + (wire + (pts + (xy 252.73 233.68) (xy 252.73 231.14) + ) + (stroke + (width 0) + (type default) + ) + (uuid "a4267dc6-bcc1-41c5-89d8-c8ac59750ff3") + ) + (label "EE_DO" + (at 252.73 231.14 90) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "007729b4-9e2e-40dc-bc45-0e669579a602") + ) + (wire + (pts + (xy 252.73 241.3) (xy 252.73 243.84) + ) + (stroke + (width 0) + (type default) + ) + (uuid "fbe82ed4-1a47-41a6-98b5-b09006c99c24") + ) + (label "EE_DATA" + (at 252.73 243.84 270) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "a05b7179-5594-41aa-a6b5-ffff2665cb5f") + ) + (wire + (pts + (xy 257.81 233.68) (xy 257.81 231.14) + ) + (stroke + (width 0) + (type default) + ) + (uuid "53724f58-c9d1-45fc-910c-c09473177b10") + ) + (label "3V3" + (at 257.81 231.14 90) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "90c061aa-52d3-4787-a837-35520f38b9e6") + ) + (wire + (pts + (xy 257.81 241.3) (xy 257.81 243.84) + ) + (stroke + (width 0) + (type default) + ) + (uuid "14104b21-2535-4c33-8f6b-c96501f0edfa") + ) + (label "EE_DO" + (at 257.81 243.84 270) + (effects + (font + (size 1.27 1.27) + ) + (justify left bottom) + ) + (uuid "6261719c-22e2-48ac-81ba-a4c21b553280") + ) )