Building Linux SBC Around STM32 Chip


The 436-ball audit is still running because the mapping must be checked ball-by-ball against ST documentation; I’m keeping the physical pad mapping unchanged while that verification completes.
Thought for 1 min 42 sec
Thought for 5 sec
Awaiting 1 background task
Thought for 5 sec
Checking Correct STM32MP257 LPDDR4 pins progress…
Thought for 7 sec
Reading Correct STM32MP257 LPDDR4 pins's report…
Thought for 10 sec — Verifying designators
Reading schematic details for DDR*.
Thought for 14 sec — Considering DDR naming conventions
Reading schematic details for CA*, CK*, CS*.
Reading schematic details for DDR_A*.
Getting a schematic overview for P*.
"STM32 LPDDR4 Pin Mapping" completed.
I’ve reconciled the completed correction with the live part: the old DDR_Ax terminals are gone and the CA/CKE/CS mappings are present. I’m doing the final clock-pair and 436-terminal integrity check now.
Fixed the STM32MP257FAI3 LPDDR4 pin naming issue. All 31 abstract DDR_Ax terminals were replaced with ST AN5723-aligned names for:
  • Channel A/B CA, CKE, and CS
  • Differential clocks CLKA_C/T and CLKB_C/T
  • Explicit LPDDR4_NC_A25 through LPDDR4_NC_A31
All 436 terminals remain present, BGA ball numbers and footprint mappings are unchanged, no DDR_Ax labels remain, and terminal review checks pass without errors or warnings. I also filed a part-quality report for engineering review.

Name
Pin #
Type
Part Type
Pin Description
Pin Orientation
VSS_1
A1
Unspecified
Terminal
Left
LVDS2_D1P
A2
Bi-Directional
Terminal
Left
LVDS2_D1N
A3
Bi-Directional
Terminal
Left
LVDS2_D0P
A4
Bi-Directional
Terminal
Left
DSI_D3P
A7
Unspecified
Terminal
Right
DSI_CKP
A8
Unspecified
Terminal
Right
PB10
A11
Unspecified
Terminal
PB9
A12
Unspecified
Terminal
PD6
A15
Unspecified
Terminal
PE0
A16
Unspecified
Terminal
PE10
A19
Unspecified
Terminal
PE14
A20
Unspecified
Terminal
PD12
A21
Unspecified
Terminal
VSS_2
A22
Unspecified
Terminal
Left
JTCK-SWCLK
AA1
Input
Terminal
Datasheet Debug input from terminal name: JTCK-SWCLK; JTAG/SWD clock input.
Right
NJTRST
AA2
Unspecified
Terminal
Right
PJ3
AA3
Bi-Directional
Terminal
Datasheet GPIO Bi-Directional from terminal name: PJ3; Bi-Directional.
Left
PG4
AA4
Unspecified
Terminal
PF10
AA6
Bi-Directional
Terminal
Datasheet GPIO from terminal name: PF10; general-purpose input/output.
PF9
AA7
Unspecified
Terminal
PF8
AA8
Unspecified
Terminal
PC6
AA10
Unspecified
Terminal
PH12
AA11
Unspecified
Terminal

STM32MP257FAI3