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Command #0C - StrobeReadCmd
VERSION less than 1.32 and 1.38+ of the firmware
Description:
Strobe read of a byte value from a port. This command selects port A or B for the read byte, as well as a polarity (negative or positive) and a line (A.0 - B.7) to toggle. The line is toggled to one state, the byte is read, and then the line is returned to the initial state.
Command Format:
| Byte Number | Description |
| 0 | 0Ch: StrobeReadCmd |
| 1 | <not used> |
| 2 | Port to write data |
| 3 | Negative⁄Positive strobe selection and strobe line selection |
| 4 | Strobe pulse length VERSION 1.38+ of the firmware |
| 5 | <not used> |
| 6 | <not used> |
| 7 | <not used> |
Command Format Details:
Byte 0 contains the command. Byte 1 is not used. Byte 2 indicates the port to write the byte. A value of 00h is port A, a value of 01h is port B.
Byte 3 contains the strobe direction and the strobe line selection.
Byte 4 contains a delay to lengthen the strobe. Valid values from 00h - FFh (0 - 255).
Byte 5 through byte 7 are unused.
Bit⁄Line Selection
| Byte Value | Result | Byte Value | Result | |
| 00h | Affect A.0 | 08h | Affect B.0 | |
| 01h | Affect A.1 | 09h | Affect B.1 | |
| 02h | Affect A.2 | 0Ah | Affect B.2 | |
| 03h | Affect A.3 | 0Bh | Affect B.3 | |
| 04h | Affect A.4 | 0Ch | Affect B.4 | |
| 05h | Affect A.5 | 0Dh | Affect B.5 | |
| 06h | Affect A.6 | 0Eh | Affect B.6 | |
| 07h | Affect A.7 | 0Fh | Affect B.7 |
With Byte 3 set to the Bit⁄Line Selection values, the strobe is negative-going. By adding 10h to this value, the strobe will be positive-going. For example: 18h would pulse B.0 from low to high, and back low.
Response Format:
| Byte Number | Description |
| 0 | 0Ch: StrobeReadCmd |
| 1 | Byte value read |
| 2 | <not used> |
| 3 | <not used> |
| 4 | <not used> |
| 5 | <not used> |
| 6 | <not used> |
| 7 | <not used> |
Response Format Details:
Byte 0 contains the command. Byte 1 contains the value read. Byte 2 through byte 7 are unused.
Example Usage:
If a device is connected to the U4xx that will send a byte of data to port A when B.7 is toggled from high to low and back to high, then the following commands would read this device.
First set the B.7 line high with a SetBitCmd command: 07-0F-00-00-00-00-00-00 The line is set high to begin with because the strobe commands do not initialize the state or direction of the line. (B.7 needs to be set as an output.)
Then toggle B.7 low, read from port A, and toggle B.7 high. 0B-00-00-0F-00-00-00-00 The breakdown of the first four bytes of the command is: 0Bh - StrobeWriteCmd, 00h - not used, 00h - port to read (A), 0Fh - line to toggle (-F) and toggle direction (0-).
Changing to a positive strobe would necessitate changing the initial line value, and substituting 1Fh for the fourth byte.
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