An overrun or underrun will terminate the current
command and the transfer of data. Disk writes will
complete the current sector by generating a 00
pattern and valid CRC. Reads require the host to
remove the remaining data so that the result
phase may be entered.
TABLE 15 - FIFO SERVICE DELAY
FIFO THRESHOLD
EXAMPLES
1 byte
MAXIMUM DELAY TO SERVICING AT
2 Mbps DATA RATE
1 x 4 μs - 1.5 μs = 2.5 μs
2 x 4 μs - 1.5 μs = 6.5 μs
8 x 4 μs - 1.5 μs = 30.5 μs
15 x 4 μs - 1.5 μs = 58.5 μs
2 bytes
8 bytes
15 bytes
FIFO THRESHOLD
EXAMPLES
1 byte
MAXIMUM DELAY TO SERVICING AT
1 Mbps DATA RATE
1 x 8 μs - 1.5 μs = 6.5 μs
2 x 8 μs - 1.5 μs = 14.5 μs
8 x 8 μs - 1.5 μs = 62.5 μs
15 x 8 μs - 1.5 μs = 118.5 μs
2 bytes
8 bytes
15 bytes
FIFO THRESHOLD
EXAMPLES
1 byte
MAXIMUM DELAY TO SERVICING AT
500 Kbps DATA RATE
1 x 16 μs - 1.5 μs = 14.5 μs
2 x 16 μs - 1.5 μs = 30.5 μs
8 x 16 μs - 1.5 μs = 126.5 μs
15 x 16 μs - 1.5 μs = 238.5 μs
2 bytes
8 bytes
15 bytes
27
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