Force Computers SYS68K/CPU-40, Руководство пользователя

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SECTION 9 APPLICATION COMMAND INTERFACE PROGRAMMING GUIDE
5-5
static void get_ccb(ccb_ptr)
struct _ccb_cservice_command *ccb_ptr;
{ while ( XTAS((char *)&ccb_ptr->_access_control_flags) != 0 )
/* allocating the CCB with a TAS */
; /* instruction */
} /* end of 'get_ccb()' */
/*
call: put_ccb(ccb_ptr)
in : ccb_ptr -> address of CCB which is no longer used
out : nothing
description:
put_ccb() makes the previous allocated CCB accessible to other
tasks.
called subroutines: none
*/
static void put_ccb(ccb_ptr)
struct _ccb_cservice_command *ccb_ptr;
{ ccb_ptr->_access_control_flags &= ~(1L << ALLOCATE);
/* the CCB is free for other */
} /* end of 'put_ccb()' */
/*
call: do_mbox0(ccb_address)
in : ccb_address -> CCB address
out : Nothing
description:
do_mbox0() initiates a Mailbox 0 interrupt. If the CCB is onboard
the interrupt will come to myself. If the CCB is offboard the
interrupt will be generated at this board.
called subroutines: none
*/
static void do_mbox0(ccb_address)
register unsigned long ccb_address;
{ if ( ccb_address < DPR_BASE ) /* ME onboard ? */
{ while ( *(char *)MAILBOX < 0 ) /* initiate an onboard Mailbox 0 */
/* interrupt */
; /* until success */
} /* do not forget this bracket */
else /* the CCB is not on this board */
{ while ( *(char *)(0xfcff0000 | ((ccb_address >> 16) & 0xff00)) < 0 )
/* initiate a VMEbus Mailbox 0 */
/* interrupt */
; /* until success */
} /* end if */
} /* end of 'do_mbox0()' */
/*
call: wait_not_busy(ccb_ptr)
in : ccb_ptr -> address of CCB which is used
out : nothing
description:
wait_not_busy() waits until someone (hopefully the ME) clears
the BUSY bit
called subroutines: none
*/