FDC37C78-HT datasheet(28/82 Pages) MICROCHIP

28 / 82 page

If the last sector to be transferred is a partial

sector, the host can stop transferring the data in

mid-sector, and the FDC will continue to complete

the sector as if a hardware TC was received. The

only difference between these implicit functions

and TC is that they return "abnormal termination"

result status.

Such status indications can be

ignored if they were expected.

Note that when the host is sending data to the

FIFO of the FDC, the internal sector count will be

complete when the FDC reads the last byte from

its side of the FIFO. There may be a delay in the

removal of the transfer request signal of up to the

time taken for the FDC to read the last 16 bytes

from the FIFO. The host must tolerate this delay.

Result Phase

The generation of IRQ determines the beginning

of the result phase. For each of the commands, a

defined set of result bytes has to be read from the

FDC before the result phase is complete. These

bytes of data must be read out for another

command to start.

RQM and DIO must both equal "1" before the

result bytes may be read. After all the result bytes

have been read, the RQM and DIO bits switch to

"1" and "0" respectively, and the CB bit is cleared,

indicating that the FDC is ready to accept the next

command.

FDC37C78-HT Datasheet(PDF) 28 Page - Microchip Technology