Difference between revisions of "83Plus:Ports:2F"
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'''Function:''' LCD Wait Delay | '''Function:''' LCD Wait Delay | ||
| − | After every write to the LCD bit 1 of [[83Plus:Ports:02|port 2]] resets for a certain amount of time. This port controls that amount time. | + | After every write to the LCD bit 1 of [[83Plus:Ports:02|port 2]] resets for a certain amount of time based on the current cpu speed and if the calculator is in hi speed mode. This port controls that amount time. |
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=== Write Values === | === Write Values === | ||
| − | * Bits 0-1 control the amount of | + | * Bits 0-1 control the amount of tstates to wait when port 20 contains 1. The following values tell the number of tstates. |
| − | ** 00 = | + | ** 00 = 048 tstates |
| − | ** 01 = | + | ** 01 = 112 tstates |
| − | ** 10 = | + | ** 10 = 176 tstates |
| − | ** 11 = | + | ** 11 = 240 tstates |
| − | * Bits 2-4 control the amount of | + | * Bits 2-4 control the amount of tstates to wait when port 20 contains 2. The following values tell the number of tstates. |
| − | ** 000 = | + | ** 000 = 048 tstates |
| − | ** 001 = | + | ** 001 = 112 tstates |
| − | ** 010 = | + | ** 010 = 176 tstates |
| − | ** 011 = | + | ** 011 = 240 tstates |
| − | ** 100 = | + | ** 100 = 304 tstates |
| − | ** 101 = | + | ** 101 = 368 tstates |
| − | ** 110 = | + | ** 110 = 432 tstates |
| − | ** 111 = | + | ** 111 = 496 tstates |
| − | * Bits 5-7 control the amount of | + | * Bits 5-7 control the amount of tstates to wait when port 20 contains 3. The following values tell the number of tstates. |
| − | ** 000 = | + | ** 000 = 048 tstates |
| − | ** 001 = | + | ** 001 = 112 tstates |
| − | ** 010 = | + | ** 010 = 176 tstates |
| − | ** 011 = | + | ** 011 = 240 tstates |
| − | ** 100 = | + | ** 100 = 304 tstates |
| − | ** 101 = | + | ** 101 = 368 tstates |
| − | ** 110 = | + | ** 110 = 432 tstates |
| − | ** 111 = | + | ** 111 = 496 tstates |
== Comments == | == Comments == | ||
Revision as of 04:27, 5 October 2005
| This port only exists as a distinct port on the TI-83 Plus Silver Edition, the TI-84 Plus, and the TI-84 Plus Silver Edition. On the standard TI-83 Plus, it acts as a shadow of port 07. |
Synopsis
Port Number: 2Fh
Function: LCD Wait Delay
After every write to the LCD bit 1 of port 2 resets for a certain amount of time based on the current cpu speed and if the calculator is in hi speed mode. This port controls that amount time.
Read Values
- This port reads the last value written to it.
Write Values
- Bits 0-1 control the amount of tstates to wait when port 20 contains 1. The following values tell the number of tstates.
- 00 = 048 tstates
- 01 = 112 tstates
- 10 = 176 tstates
- 11 = 240 tstates
- Bits 2-4 control the amount of tstates to wait when port 20 contains 2. The following values tell the number of tstates.
- 000 = 048 tstates
- 001 = 112 tstates
- 010 = 176 tstates
- 011 = 240 tstates
- 100 = 304 tstates
- 101 = 368 tstates
- 110 = 432 tstates
- 111 = 496 tstates
- Bits 5-7 control the amount of tstates to wait when port 20 contains 3. The following values tell the number of tstates.
- 000 = 048 tstates
- 001 = 112 tstates
- 010 = 176 tstates
- 011 = 240 tstates
- 100 = 304 tstates
- 101 = 368 tstates
- 110 = 432 tstates
- 111 = 496 tstates
Comments
This value really shouldn't be changed. TI-OS depends on this being set high enough to function for the LCD delay.
Also the 83+SE has this port set to 4A as default, the 84+(SE) has this port set to 4B as default.
Credits and Contributions
- James Montelongo
