# AERIS-10 XC7A50T Production Bitstream

**File:** `xc7a50t-ftg256-prod-2026-04-18.bit`  
**Date:** 2026-04-18  
**Commit:** d0b3a4c (fix/adar1000-channel-rotation)  
**Target:** XC7A50T-2FTG256C (production 50T board)  
**Top module:** `radar_system_top_50t` (USB_MODE=1, FT2232H)

## Build Summary

| Metric | Value |
|--------|-------|
| WNS (setup, 400 MHz clk_dco) | +0.020 ns |
| WHS (hold, 400 MHz clk_dco) | +0.035 ns |
| WPWS (pulse width) | +0.361 ns |
| Failing endpoints | 0 |
| DRC errors | 0 |
| Critical Warnings | 0 |
| Synth time | 152 s |
| Impl time | 416 s |
| Bitstream size | 2140 KB |
| Vivado | 2025.2 |

## Key Changes vs Previous Build

- **400 MHz reset fan-out fix**: `reset_h` registered active-high reset with
  `(* max_fanout=50 *)` in `nco_400m_enhanced`, `cic_decimator_4x_enhanced`,
  and `ddc_400m`. Resolves prior WNS=-0.626 ns caused by single-LUT1 / 700+
  load reset net. Vivado replicates into regional copies, each driving ≤50 loads.
- **Default USB interface**: `radar_system_top` parameter `USB_MODE` changed
  from 0 (FT601) to 1 (FT2232H). FT601 remains selectable via explicit override
  for the 200T premium board.

## Programming

```tcl
open_hw_manager
connect_hw_server
open_hw_target
set_property PROGRAM.FILE {xc7a50t-ftg256-prod-2026-04-18.bit} [current_hw_device]
program_hw_devices [current_hw_device]
```

## Verification Steps

1. Confirm DONE pin asserts after programming
2. Check FT2232H CLKOUT (60 MHz) present on ft_clkout pin
3. Confirm heartbeat toggle on system_status[0] (~0.4 Hz at 100 MHz)
4. Issue status request opcode 0xFF over FT2232H; verify 26-byte status packet
5. Check DIG_6 GPIO tracks host AGC enable state