User`s manual

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) 8. Hardware buffer
8.1 adt8840a_reset_fifo( )
Name int adt8840a_reset_fifo(int dev_num)
Definition Reset buffer. In other words, clear all commands in the buffer.
Input parameter dev_num: device number
Output
parameter
None
Return value 0: execution OK; -1: transmission abnormity; -4: disabled device interface
Note
Clearing FIFO (first-in-first-out) is only to clear the data in the buffer, and it won’t stop the
current motion.
8.2 adt8840a_read_fifo( )
Name int adt8840a_read_fifo(int dev_num, UINT *value)
Definition Get to know buffer’s space used
Input parameter None
Output
parameter
dev_num: device number
value: space used
The value indicates the status of FIFO, whose definitions are as follows:
D15: full D14: almost full D13: empty D12: almost empty
Full—FIFO is full and nor more data can be written (normally not used);
Almost full—The remaining space of FIFO is less than 8 (used for judging whether more
data can be placed into FIFO);
Empty—There are no data in FIFO (used for judging whether FIFO is empty);
Almost empty—The remaining data in FIFO are less than 8 (normally not used).
The above statuses can be judged by referring to the data saved in FIFO.
“Byte” is used as the unit of data, with 2048 bytes for maximum. The number of the bytes is
subject to the interpolation command:
fifo_inp_move1: 3 byte
fifo_inp_move2: 4 byte
fifo_inp_move3: 5 byte
fifo_inp_move4: 6 byte
Return value
0: execution OK; 1: execution failure; -1: transmission abnormity; -2: response overtime;
-3: abnormal data received; -4: disabled device interface
Note
Clearing FIFO (first-in-first-out) is only to clear the data in the buffer, and it won’t stop the
current motion.
8.3 adt8840a_ fifo_inp_move1()