Difference between revisions of "83Plus:Ports:08"
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=== Read Values === | === Read Values === | ||
| + | * Bit 1: 1 if link assist will generate an interrupt when a byte is received.(Link assist must be enabled) | ||
* Bit 7: 1 if the link assist is disabled. | * Bit 7: 1 if the link assist is disabled. | ||
=== Write Values === | === Write Values === | ||
| + | * Bit 1: Set to generate an interrupt when link assist receives a byte.(Link assist must be enabled) | ||
* Bit 7: 1 to disable the link assist. | * Bit 7: 1 to disable the link assist. | ||
| Line 17: | Line 19: | ||
Programs which directly control the link port should disable the hardware assist. | Programs which directly control the link port should disable the hardware assist. | ||
| + | |||
| + | ===Interrupts=== | ||
| + | Link Assist hardware can generate an interrupt when a byte is recieved. To enable this write 01 to port 08. When a byte recieved and an interrupt is generated bit 0 of port 9 is set. Like all interrupts this one needs to be acknowledged, do this by reading the byte from port 0A. | ||
| + | |||
== Credits and Contributions == | == Credits and Contributions == | ||
* '''Michael Vincent:''' Original documentation of the link assist | * '''Michael Vincent:''' Original documentation of the link assist | ||
Revision as of 17:21, 22 July 2005
Contents
Synopsis
Port Number: 08h
Function: Link Assist Enable
This port controls whether the hardware link assist is enabled.
Read Values
- Bit 1: 1 if link assist will generate an interrupt when a byte is received.(Link assist must be enabled)
- Bit 7: 1 if the link assist is disabled.
Write Values
- Bit 1: Set to generate an interrupt when link assist receives a byte.(Link assist must be enabled)
- Bit 7: 1 to disable the link assist.
Comments
This port only exists on the 83+ SE and the 84+.
Programs which directly control the link port should disable the hardware assist.
Interrupts
Link Assist hardware can generate an interrupt when a byte is recieved. To enable this write 01 to port 08. When a byte recieved and an interrupt is generated bit 0 of port 9 is set. Like all interrupts this one needs to be acknowledged, do this by reading the byte from port 0A.
Credits and Contributions
- Michael Vincent: Original documentation of the link assist
