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| author |   Wade Fife <wade.fife@ettus.com> | 2020-08-10 09:31:26 -0500 |
|---|---|---|
| committer | Wade Fife <wade.fife@ettus.com> | 2020-08-11 16:20:51 -0500 |
| commit | 4f387c8ff0571deedc86dc459e94e555b9768282 (patch) | |
| tree | 4ee19e2843b43d4c986465acab09243bec588be3 | |
| parent | examples: replay samples from file (diff) | |
| download | uhd-4f387c8ff0571deedc86dc459e94e555b9768282.tar.xz uhd-4f387c8ff0571deedc86dc459e94e555b9768282.zip | |
fpga: lib: Change max FFT size to 1024
The max FFT size was 4096, but we don't currently have any devices that
can do that without modification. This is because, currently, the FFT
size must be the same as the packet size, and the largest packet
size supported by most devices is about 8000 bytes, or 2000
sc16 samples. Therefore, the largest FFT size supported without
modifying other code is 1024 samples.
This change frees up about 21% of the LUTs and 36% of the BRAM used by
axi_fft and makes the software block controller and the IP agree on the
maximum FFT size.
| -rw-r--r-- | fpga/usrp3/lib/ip/axi_fft/axi_fft.xci | 4 | ||||
| -rw-r--r-- | host/lib/rfnoc/fft_block_control.cpp | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/fpga/usrp3/lib/ip/axi_fft/axi_fft.xci b/fpga/usrp3/lib/ip/axi_fft/axi_fft.xci index 8de860b98..a33d90005 100644 --- a/fpga/usrp3/lib/ip/axi_fft/axi_fft.xci +++ b/fpga/usrp3/lib/ip/axi_fft/axi_fft.xci @@ -95,7 +95,7 @@ <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_M_AXIS_DATA_TDATA_WIDTH">32</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_M_AXIS_DATA_TUSER_WIDTH">16</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_M_AXIS_STATUS_TDATA_WIDTH">1</spirit:configurableElementValue> - <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_NFFT_MAX">12</spirit:configurableElementValue> + <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_NFFT_MAX">10</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_OPTIMIZE_GOAL">0</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_OUTPUT_WIDTH">16</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="MODELPARAM_VALUE.C_REORDER_MEM_TYPE">1</spirit:configurableElementValue> @@ -131,7 +131,7 @@ <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.target_clock_frequency">200</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.target_data_throughput">50</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.throttle_scheme">nonrealtime</spirit:configurableElementValue> - <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.transform_length">4096</spirit:configurableElementValue> + <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.transform_length">1024</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="PARAM_VALUE.xk_index">true</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="PROJECT_PARAM.ARCHITECTURE">kintex7</spirit:configurableElementValue> <spirit:configurableElementValue spirit:referenceId="PROJECT_PARAM.BASE_BOARD_PART"/> diff --git a/host/lib/rfnoc/fft_block_control.cpp b/host/lib/rfnoc/fft_block_control.cpp index 867d458ca..23ee380ac 100644 --- a/host/lib/rfnoc/fft_block_control.cpp +++ b/host/lib/rfnoc/fft_block_control.cpp @@ -22,7 +22,7 @@ constexpr int DEFAULT_FFT_SCALING = 1706; // Conservative 1/N scaling // FFT IP constraints constexpr int MIN_FFT_LENGTH = 8; -constexpr int MAX_FFT_LENGTH = 2048; +constexpr int MAX_FFT_LENGTH = 1024; const uhd::rfnoc::io_type_t DEFAULT_TYPE = uhd::rfnoc::IO_TYPE_SC16; |