Texas Instruments MSP53C391, Руководство пользователя

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Master Microprocessor Interface Description
2-9 MSP53C391 Hardware Description
Write Operation
1) The master microprocessor should clear all pending interrupts and enable
the external interrupt.
2) The master microprocessor writes the first nibble of data by presenting
valid data on DATA0 – DATA3, tying R/W to ground indicates a write opera-
tion and pulsing STROB low and high to latch the data into the
MSP53C391 input latch.
Subsequent data is written following the falling edge of the IRQ signal.
3) The master microprocessor waits for a falling edge on the IRQ signal.
4) The master microprocessor checks the EOS signal to verify that the end-
of-speech has not been reached. If the EOS is high, the end-of-speech
has been reached and the master microprocessor should stop trying to
send data and should reset the MSP53C391 as described in the following.
If the EOS is low, the end-of-speech has not been reached and the write
operation should continue with step 5.
5) Tie R/W to ground indicates a write operation
6) The master microprocessor presents valid data to the four data pins
(DATA0 – DATA3).
7) The master microprocessor pulses the STROB signal low and then high
to latch the data to the MSP53C391 input data latch.
If the EOS signal is asserted high in step 4 (shown previously), the end-of-
speech has been reached and a reset operation should be performed prior to
sending new commands or speech data. The reset can be done in one of two
ways: Pulsing the INIT pin low and then waiting for the MSP53C391 to re-ini-
tialize itself or by writing two dummy bytes to the MSP53C391.