Advantech PCL-818 Series, User Manual

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61 Appendix C
C.18 FIFO Status — BASE+19H
The register at BASE+19H clears the FIFO buffer and sets its empty flag
(EF). The FIFO status register, address BASE+19H, has flags which you
can read to determine the current state of the FIFO buffer, including full
flag, half-full flag, and empty flag.
Table C-17 Register for FIFO Status
EF FIFO empty flag
1 FIFO is empty
0 FIFO is not empty
HF FIFO half-full flag
1 FIFO is half-full or more than half-full
0 FIFO is less than half-full
FF FIFO full flag
1 FIFO is full
0 FIFO is not full
Read FIFO status
Bit # 7 6 5 4 3 2 1 0
BASE + 19H FF HF EF
Note: This register is not used for PCL-818L.