Digital I/O Wildcard User Guide
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Forth Code to control the Digital I/O Wildcard
HEX
| 1 | CONSTANT OUTPUT_HIGH |
| 0 | CONSTANT OUTPUT_LOW |
| |
| C000
| CONSTANT NIBBLE_0_ADDR
| \ Lines 0-3. |
| C001
| CONSTANT NIBBLE_1_ADDR
| \ Lines 4-7. |
| C002
| CONSTANT NIBBLE_2_ADDR
| \ Lines 8-11. |
| C003
| CONSTANT NIBBLE_3_ADDR
| \ Lines 12-15. |
| C004
| CONSTANT NIBBLE_4_ADDR
| \ Lines 16-19. Inputs only. |
| 1 | CONSTANT LINE_0 |
| 2 | CONSTANT LINE_1 |
| 4 | CONSTANT LINE_2 |
| 8 | CONSTANT LINE_3 |
| 1 | CONSTANT LINE_4 |
| 2 | CONSTANT LINE_5 |
| 4 | CONSTANT LINE_6 |
| 8 | CONSTANT LINE_7 |
| 1 | CONSTANT LINE_8 |
| 2 | CONSTANT LINE_9 |
| 4 | CONSTANT LINE_10 |
| 8 | CONSTANT LINE_11 |
| 1 | CONSTANT LINE_12 |
| 2 | CONSTANT LINE_13 |
| 4 | CONSTANT LINE_14 |
| 8 | CONSTANT LINE_15 |
| : Control_DIO ( byte1\u\byte2\byte3 -- ) |
| \ Sets I/O line of specified nibble to the appropriate state (high or low). |
| \ byte1 = module number, u = nibble address, byte2 = line, byte3 = state. |
| \ Valid module numbers are 0-7. |
| \ Valid nibble addresses are NIBBLE_0_ADDR to NIBBLE_3_ADDR. |
| \ Valid lines are LINE_0 to LINE_15 |
| \ Valid states are OUTPUT_HIGH or OUTPUT_LOW |
| locals{ &state &line &nibble_addr &module } |
| &state |
| IF | \ set line high |
&line &nibble_addr &module SET.BITS
| ELSE | \ set line low |
| &line &nibble_addr &module CLEAR.BITS |
| ENDIF |
| ; |
: Read_Nibble ( byte1\u –- byte2 | byte1 = module number, u = nibble addr )
\ Reads the current state of the Digital I/O nibble.
\ Valid module numbers are 0-7.
\ Valid nibble addresses are NIBBLE_0_ADDR to NIBBLE_4_ADDR.
\ Returns an unsigned character whose least significant nibble represents
\ the four I/O lines. For example, if nibble 1 is read and a 1 is returned
\ (0001 in binary), then line 4 is high and lines 5-7 are low. If 12 is
\ returned (1100 in binary) after reading nibble 3, then lines 12 and 13 are
\ low and lines 14 and 15 are high. The four most significant bits of the
\ returned byte do not matter.
locals{ &nibble_addr &module }
&nibble_addr &module C@
| ;
| | | | | | | | | | | | | | |
Conclusion
Now you are ready to start using your Digital I/O Wildcard. All of the software routines listed in this document are also on the distribution CD that accompanies each Wildcard.
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