Implements the STM32 outer-loop AGC (ADAR1000_AGC) that reads the FPGA
saturation flag on DIG_5/PD13 once per radar frame and adjusts the
ADAR1000 VGA common gain across all 16 RX channels.
Phase 4 — ADAR1000_AGC class (new files):
- ADAR1000_AGC.h/.cpp: attack/recovery/holdoff logic, per-channel
calibration offsets, effectiveGain() with OOB safety
- test_agc_outer_loop.cpp: 13 tests covering saturation, holdoff,
recovery, clamping, calibration, SPI spy, reset, mixed sequences
Phase 5 — main.cpp integration:
- Added #include and global outerAgc instance
- AGC update+applyGain call between runRadarPulseSequence() and
HAL_IWDG_Refresh() in main loop
Build system & shim fixes:
- Makefile: added CXX/CXXFLAGS, C++ object rules, TESTS_WITH_CXX in
ALL_TESTS (21 total tests)
- stm32_hal_mock.h: const uint8_t* for HAL_UART_Transmit (C++ compat),
__NOP() macro for host builds
- shims/main.h + real main.h: FPGA_DIG5_SAT pin defines
All tests passing: MCU 21/21, GUI 92/92, cross-layer 29/29.
Bug #11: platform_noos_stm32.c used HAL_SPI_Transmit instead of
HAL_SPI_TransmitReceive — reads returned garbage. Changed to in-place
full-duplex. Dead code (never called), fixed per audit recommendation.
Test added: test_bug11_platform_spi_transmit_only.c. Mock infrastructure
updated with SPI spy types. All 11 firmware tests pass.
FPGA B2: Migrated long_chirp_lut[0:3599] from ~700 lines of hardcoded
assignments to BRAM with (* ram_style = "block" *) attribute and
$readmemh("long_chirp_lut.mem"). Added sync-only read block for proper
BRAM inference. 1-cycle read latency introduced. short_chirp_lut left
as distributed RAM (60 entries, too small for BRAM).
FPGA B3: Added BREG (window_val_reg) and MREG (mult_i_raw/mult_q_raw)
pipeline stages to doppler_processor.v. Eliminates DPIP-1 and DPOP-2
DRC warnings. S_LOAD_FFT retimed: fft_input_valid starts at sub=2,
+1 cycle total latency. BREG primed in S_PRE_READ at no extra cost.
Both FPGA files compile clean with Icarus Verilog.
Jason