| /* |
| * Copyright (C) 2017-2020 The Project X-Ray Authors. |
| * |
| * Use of this source code is governed by a ISC-style |
| * license that can be found in the LICENSE file or at |
| * https://opensource.org/licenses/ISC |
| * |
| * SPDX-License-Identifier: ISC |
| */ |
| #include <prjxray/xilinx/xc7series/ecc.h> |
| #include <cassert> |
| #include <cstdio> |
| |
| namespace prjxray { |
| namespace xilinx { |
| namespace xc7series { |
| |
| constexpr size_t kECCFrameNumber = 0x32; |
| |
| uint32_t icap_ecc(uint32_t idx, uint32_t data, uint32_t ecc) { |
| uint32_t val = idx * 32; // bit offset |
| |
| if (idx > 0x25) // avoid 0x800 |
| val += 0x1360; |
| else if (idx > 0x6) // avoid 0x400 |
| val += 0x1340; |
| else // avoid lower |
| val += 0x1320; |
| |
| if (idx == 0x32) // mask ECC |
| data &= 0xFFFFE000; |
| |
| for (int i = 0; i < 32; i++) { |
| if (data & 1) |
| ecc ^= val + i; |
| |
| data >>= 1; |
| } |
| |
| if (idx == 0x64) { // last index |
| uint32_t v = ecc & 0xFFF; |
| v ^= v >> 8; |
| v ^= v >> 4; |
| v ^= v >> 2; |
| v ^= v >> 1; |
| ecc ^= (v & 1) << 12; // parity |
| } |
| |
| return ecc; |
| } |
| |
| static uint32_t calculateECC(const std::vector<uint32_t>& data) { |
| uint32_t ecc = 0; |
| for (size_t ii = 0; ii < data.size(); ++ii) { |
| ecc = xc7series::icap_ecc(ii, data[ii], ecc); |
| } |
| return ecc; |
| } |
| |
| void updateECC(std::vector<uint32_t>& data) { |
| assert(data.size() >= kECCFrameNumber); |
| // Replace the old ECC with the new. |
| data[kECCFrameNumber] &= 0xFFFFE000; |
| data[kECCFrameNumber] |= (calculateECC(data) & 0x1FFF); |
| } |
| |
| } // namespace xc7series |
| } // namespace xilinx |
| } // namespace prjxray |