26 lines
685 B
Plaintext
26 lines
685 B
Plaintext
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;
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; Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
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;
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; SPDX-License-Identifier: BSD-3-Clause
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;
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.program ws2812
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.side_set 1
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.define public T1 2
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.define public T2 5
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.define public T3 3
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.lang_opt python sideset_init = pico.PIO.OUT_HIGH
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.lang_opt python out_init = pico.PIO.OUT_HIGH
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.lang_opt python out_shiftdir = 1
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.wrap_target
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bitloop:
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out x, 1 side 0 [T3 - 1] ; Side-set still takes place when instruction stalls
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jmp !x do_zero side 1 [T1 - 1] ; Branch on the bit we shifted out. Positive pulse
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do_one:
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jmp bitloop side 1 [T2 - 1] ; Continue driving high, for a long pulse
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do_zero:
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nop side 0 [T2 - 1] ; Or drive low, for a short pulse
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.wrap
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