Difference between revisions of "83Plus:Ports:03"

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(Credits and Contributions)
(Write Values)
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=== Write Values ===
 
=== Write Values ===
 
* Bit 0: Set 1 to enable the ON key. Set 0 to disable it.
 
* Bit 0: Set 1 to enable the ON key. Set 0 to disable it.
* Bit 1: Set 1 to enable the hardware timer. Set 0 to disable it.
+
* Bit 1: Set 1 to enable the first hardware timer. Set 0 to disable it.
 +
* Bit 2: Set 1 to enable the second hardware timer. Set 0 to disable it.
 
* Bit 3: Set 1 to enable the LCD. Set 0 to turn off the LCD.
 
* Bit 3: Set 1 to enable the LCD. Set 0 to turn off the LCD.
 
* Bit 4: Set 1 to enable the linkport interrupt. Set 0 to disable it. (Does not completely disable the linkport.)
 
* Bit 4: Set 1 to enable the linkport interrupt. Set 0 to disable it. (Does not completely disable the linkport.)

Revision as of 15:42, 28 March 2005

Synopsis

Port Number: 03h

Function: Interrupt Masking Port

This port controls what devices will be allowed to trigger interrupts.

Read Values

  • Bit 0: Set if pressing the ON key will generate an interrupt.
  • Bit 1: Set if the first hardware timer will generate an interrupt (range: 108Hz-512Hz).
  • Bit 2: Set if the second hardware timer will generate an interrupt (range: 216Hz-1024Hz).
  • Bit 4: Set if the linkport will generate an interrupt.

Write Values

  • Bit 0: Set 1 to enable the ON key. Set 0 to disable it.
  • Bit 1: Set 1 to enable the first hardware timer. Set 0 to disable it.
  • Bit 2: Set 1 to enable the second hardware timer. Set 0 to disable it.
  • Bit 3: Set 1 to enable the LCD. Set 0 to turn off the LCD.
  • Bit 4: Set 1 to enable the linkport interrupt. Set 0 to disable it. (Does not completely disable the linkport.)

Comments

For normal operation, write 0B (00001011) to this port.

Example

This example shows how to do a soft powerdown (similar to the auto powerdown) on the calculator. This may or may not wipe the LCD screen, so you should first copy it's contents to a buffer like saveSScreen and then copy it back afterwards.

 push af
 ld a, 11h ;Enable linkport, ON key. Disable timer. Turn off LCD.
 out (3), a
 halt ;Wait for an interrupt (either ON key or insert link cable).
 ld a, 0Bh ;Enable ON key, timer. Disable linkport. Turn on LCD.
 out (3), a
 pop af

Credits and Contributions

Michael Vincent: For documenting here on the interrupt bits. James Montelongo: For documenting here on the interrupt bits.