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authorwdenk <wdenk>2001-11-28 17:49:55 +0000
committerwdenk <wdenk>2001-11-28 17:49:55 +0000
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+CONTENT:
+
+ epic.h
+ epic1.c
+ epic2.s
+
+WHAT ARE THESE FILES:
+
+These files contain MPC8240 (Kahlua) EPIC
+driver routines. The driver routines are not
+written for any specific operating system.
+They serves the purpose of code sample, and
+jump-start for using the MPC8240 EPIC unit.
+
+For the reason of correctness of C language
+syntax, these files are compiled by Metaware
+C compiler and assembler.
+
+ENDIAN NOTATION:
+
+The algorithm is designed for big-endian mode,
+software is responsible for byte swapping.
+
+USAGE:
+
+1. The host system that is running on MPC8240
+ shall link the files listed here. The memory
+ location of driver routines shall take into
+ account of that driver routines need to run
+ in supervisor mode and they process external
+ interrupts.
+
+ The routine epic_exception shall be called by
+ exception vector at location 0x500, i.e.,
+ 603e core external exception vector.
+
+2. The host system is responsible for configuring
+ the MPC8240 including Embedded Utilities Memory
+ Block. All EPIC driver functions require the
+ content of Embedded Utilities Memory Block
+ Base Address Register, EUMBBAR, as the first
+ parameter.
+
+3. Before EPIC unit of MPC8240 can be used,
+ initialize EPIC unit by calling epicInit
+ with the corresponding parameters.
+
+ The initialization shall disable the 603e
+ core External Exception by calling CoreExtIntDisable( ).
+ Next, call epicInit( ). Last, enable the 603e core
+ External Exception by calling CoreExtIntEnable( ).
+
+4. After EPIC unit has been successfully initialized,
+ epicIntSourceSet( ) shall be used to register each
+ external interrupt source. Anytime, an external
+ interrupt source can be disabled or enabled by
+ calling corresponding function, epicIntDisable( ),
+ or epicIntEnable( ).
+
+ Global Timers' resource, base count and frequency,
+ can be changed by calling epicTmFrequencySet( )
+ and epicTmBaseSet( ).
+
+ To stop counting a specific global timer, use
+ the function, epicTmInhibit while epicTmEnable
+ can be used to start counting a timer.
+
+5. To mask a set of external interrupts that are
+ are certain level below, epicIntPrioritySet( )
+ can be used. For example, if the processor's
+ current task priority register is set to 0x7,
+ only interrupts of priority 0x8 or higher will
+ be passed to the processor.
+
+ Be careful when using this function. It may
+ corrupt the current interrupt pending, selector,
+ and request registers, resulting an invalid vetor.
+
+ After enabling an interrupt, disable it may also
+ cause an invalid vector. User may consider using
+ the spurious vector interrupt service routine to
+ handle this case.
+
+6. The EPIC driver routines contains a set
+ of utilities, Set and Get, for host system
+ to query and modify the desired EPIC source
+ registers.
+
+7. Each external interrupt source shall register
+ its interrupt service routine. The routine
+ shall contain all interrupt source specific
+ processes and keep as short as possible.
+
+ Special customized end of interrupt routine
+ is optional. If it is needed, it shall contain
+ the external interrupt source specific end of
+ interrupt process.
+
+ External interrupt exception vector at 0x500
+ shall always call the epicEOI just before
+ rfi instruction. Refer to the routine,
+ epic_exception, for a code sample.
+
+