Description This command enables ?ow control. When the buff
er ?lls so that only
[full] bytes are available, the display will return an “almost full”
message (0xFE) to the host controller. When the buffer empties so that
only [empty] bytes remain, the display will return an “almost empty”
message (0xFF) to the host controller.
The display will return the “almost full” message for every b
yte sent to
the display until the used buffer space once more drops below
the [full]
level. Whether the user is in `?ow control mode' or not, the mo
dule will
ignore display or command bytes which would overrun the buffer.
While in `?ow control mode' the unit will return 0xFE when buf
fer is
almost full even though it may have already thrown rejected data away.
The buffer size for the display is 128 bytes.
When using this command in an application, selection of the value for
the buffer [full] should be considered very carefully. This
is a critical
aspect to be able to use this feature to it's full potential. When using a
host system or PC which contains a FIFO, the user should set the value
of [full] equal to or greater than the size of the FIFO. The reason for this
is that the FIFO may be full when the host system receives 0xFE. In the
case of 16550 UART the size at its maximum is 16, therefore the
value
of [full] should be set to 16 or greater. It is suggested that the “almost
full” parameter be equal to the largest chunk of data the host
will be
sending the display (should be less than 127).
NOTE
This command is not available in I2C mode.
Remembered Yes
Default Off
4.3 Turn Flow Control Off
Syntax
Hexadecimal 0xFE 0x3B
Decimal 254 59
ASCII 254 “;”
Description This command turns off ?ow control. Bytes may ov
er?ow the buffer
without warning.
NOTE
This command is not available in I2C mode.
Remembered Yes
4.4 Changing the I2C Slave Address
Matrix Orbital GLK12232-25-SM
16