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104 lines
2.0 KiB
Plaintext
104 lines
2.0 KiB
Plaintext
# SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
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# SPDX-License-Identifier: Unlicense OR CC0-1.0
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# Example bitscrambler program. Reads in 8 bytes and spits out 8 bytes are
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# the 'rotated' version of the input bytes. Specifically, output byte 0
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# consists of bit 0 of input byte 0, bit 0 of input byte 1, bit 0 of input
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# byte 2 etc. Output byte 1 consists of bit 1 of input byte 0, bit 1 of
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# input byte 1, bit 1 of input byte 2, etc.
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cfg eof_on downstream
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cfg trailing_bytes 8 #If we have an EOF on the input, we still
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#need to process the 64 bits in M0/M1
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cfg prefetch true #We expect M0/M1 to be filled
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loop:
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# Note: we start with 64 bits in M0 and M1, so we can immediately start outputting.
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#output byte 0
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set 0 0,
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set 1 8,
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set 2 16,
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set 3 24,
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set 4 32,
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set 5 40,
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set 6 48,
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set 7 56,
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#output byte 1
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set 8 1,
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set 9 9,
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set 10 17,
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set 11 25,
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set 12 33,
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set 13 41,
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set 14 49,
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set 15 57,
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#output byte 2
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set 16 2,
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set 17 10,
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set 18 18,
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set 19 26,
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set 20 34,
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set 21 42,
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set 22 50,
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set 23 58,
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#output byte 3
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set 24 3,
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set 25 11,
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set 26 19,
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set 27 27,
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set 28 35,
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set 29 43,
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set 30 51,
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set 31 59,
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#as we can only write 32 bits at the same time, we write these and
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#route the other 32 bits in the next instruction.
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write 32
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#2nd instruction: route the other 32 bits and write.
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#output byte 4
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set 0 4,
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set 1 12,
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set 2 20,
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set 3 28,
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set 4 36,
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set 5 44,
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set 6 52,
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set 7 60,
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#output byte 5
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set 8 5,
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set 9 13,
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set 10 21,
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set 11 29,
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set 12 37,
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set 13 45,
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set 14 53,
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set 15 61,
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#output byte 6
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set 16 6,
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set 17 14,
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set 18 22,
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set 19 30,
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set 20 38,
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set 21 46,
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set 22 54,
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set 23 62,
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#output byte 7
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set 24 7,
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set 25 15,
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set 26 23,
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set 27 31,
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set 28 39,
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set 29 47,
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set 30 55,
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set 31 63,
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#Write these last 32 bits.
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write 32,
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#Note we can read the first half of the next 64 bits into the
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#input buffer as the load happens at the end of the instruction.
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read 32
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#Read the 2nd half of the 64 bits in, and loop back to the start.
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read 32,
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jmp loop
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