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Please don't shout, we're all deaf here, anyway. :) Your understanding of IRQ is good. XIRQ is similar to IRQ with some exceptions: 1. Once enabled, XIRQ cannot be disabled (actually it can be, but it shouldn't in theory as it said to be a non-maskable interrupt). Its purpose is to handle disasterous situations, such as power failure, external hardware failure, etc. 2. Unlike other interrupts XIRQ will interrupt even another executing interrupt handler (regardless of the state of the CCR-I bit). This guarantees immediate attention at any time. 3. XIRQ is level sensitive. IRQ can be configured as either level or edge sensitive. Both need a pullup and are active low. ----- Original Message ----- From: "MIKE" <> To: < > I WAS WANTING TO KNOW IF IM UNDERSTANDING THE OPERATION OF THE IRQ > PIN41 ON THE HC11. FROM WHAT I HAVE READ THE PIN IS USED TO SEND A > INTERRUPT REQUEST TO THE HC11, AND THIS REQUEST HAS TO BE SERVICED AT > THE IRQ VECTOR $00EE BUFFALO & $FFF2,$FFF3 EXPANDED MODE. ALSO I HAVE > NOT BEEN ABLE TO FIND AN INFO ON THE DIFFERENCE BETWEEN IRQ PIN AND > THE XIRQ IF THERES SOME ONE WHO CAN SHED A LITTLE LIGHT ON THESE > REQUEST ID APPRECIATE IT MUCH. |
Re: HC11 IRQ AND XIRQ PIN 40 AND 41
Started by ●September 21, 2003
Reply by ●September 21, 20032003-09-21
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I WAS WANTING TO KNOW IF IM UNDERSTANDING THE OPERATION OF THE IRQ PIN41 ON THE HC11. FROM WHAT I HAVE READ THE PIN IS USED TO SEND A INTERRUPT REQUEST TO THE HC11, AND THIS REQUEST HAS TO BE SERVICED AT THE IRQ VECTOR $00EE BUFFALO & $FFF2,$FFF3 EXPANDED MODE. ALSO I HAVE NOT BEEN ABLE TO FIND AN INFO ON THE DIFFERENCE BETWEEN IRQ PIN AND THE XIRQ IF THERES SOME ONE WHO CAN SHED A LITTLE LIGHT ON THESE REQUEST ID APPRECIATE IT MUCH. |
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Reply by ●September 21, 20032003-09-21
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In a message dated 9/21/03 6:28:04 PM Eastern Daylight Time, writes: NOT BEEN ABLE TO FIND AN INFO ON THE DIFFERENCE BETWEEN IRQ PIN AND THE XIRQ IF THERES SOME ONE WHO CAN SHED A LITTLE LIGHT ON THESE REQUEST ID APPRECIATE IT MUCH. =============================================== I know you dont want someone to tell you to read the fine manual, but you can dowload it from the motorola site... tells all about how the hc11 works... here's a hint... xirq needs to be enabled in a special way and cant be masked on and off with a cli and sei |
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