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Adding a delay such as the 20ms one we have in AVR programmer's initialization routine is tricky without a word like TICKS. This implementation is highly inaccurate, but more accurate and reliable than a "ballpark" DO..LOOP...
14 lines
527 B
Plaintext
14 lines
527 B
Plaintext
( The word below is designed to wait the proper 100us per tick
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at 500kHz when tickfactor is 1. If the CPU runs faster,
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tickfactor has to be adjusted accordingly. "t" in comments
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below means "T-cycle", which at 500kHz is worth 2us. )
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CODE TICKS
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HL POP, chkPS,
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( we pre-dec to compensate for initialization )
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BEGIN,
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HL DECd, ( 6t )
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IFZ, ( 12t ) JPNEXT, THEN,
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A tickfactor @ LDri, ( 7t )
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BEGIN, A DECr, ( 4t ) JRNZ, ( 12t ) AGAIN,
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JR, ( 12t ) AGAIN, ( outer: 37t inner: 16t )
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