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EMJB
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TAP_Print Execution Time

Post by EMJB »

It would help me optimise he speed of my SerialTransfer TAP if I understood the execution time of the TAP_Print function. It seems to me that there are 3 broad possibilities:

(1) It puts the resulting string into some pseudo-infinite buffer, and then exits immediately, leaving lower level activities to transfer data out to the hardware as the latter needs it.

(2) It keeps a short (8 byte?) hardware buffer full as the data is transmitted, and only exits when the last character has been put it that buffer.

(3) It only exits as the last character is being transmitted.

My suspicion is that either 2 or 3 is correct, but does anyone know?

TIA,

EMJB
R2-D2
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Post by R2-D2 »

Sends each character individually by waiting for the EMMA2 hardware register Trans. Holding Reg Empty to be asserted (in a very tight loop) then writes the character to the EMMA2 data register.
EMJB
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Post by EMJB »

Thanks R2-D2 - that's what I feared,

EMJB
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