248 lines
6.3 KiB
C
248 lines
6.3 KiB
C
/* Lattice Mico32 CPU model.
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Contributed by Jon Beniston <jon@beniston.com>
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Copyright (C) 2009-2015 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "hw-main.h"
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#include "sim-main.h"
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struct lm32cpu
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{
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struct hw_event *event;
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};
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/* input port ID's. */
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enum
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{
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INT0_PORT,
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INT1_PORT,
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INT2_PORT,
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INT3_PORT,
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INT4_PORT,
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INT5_PORT,
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INT6_PORT,
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INT7_PORT,
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INT8_PORT,
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INT9_PORT,
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INT10_PORT,
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INT11_PORT,
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INT12_PORT,
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INT13_PORT,
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INT14_PORT,
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INT15_PORT,
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INT16_PORT,
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INT17_PORT,
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INT18_PORT,
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INT19_PORT,
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INT20_PORT,
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INT21_PORT,
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INT22_PORT,
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INT23_PORT,
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INT24_PORT,
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INT25_PORT,
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INT26_PORT,
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INT27_PORT,
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INT28_PORT,
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INT29_PORT,
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INT30_PORT,
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INT31_PORT,
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};
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static const struct hw_port_descriptor lm32cpu_ports[] = {
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/* interrupt inputs. */
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{"int0", INT0_PORT, 0, input_port,},
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{"int1", INT1_PORT, 0, input_port,},
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{"int2", INT2_PORT, 0, input_port,},
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{"int3", INT3_PORT, 0, input_port,},
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{"int4", INT4_PORT, 0, input_port,},
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{"int5", INT5_PORT, 0, input_port,},
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{"int6", INT6_PORT, 0, input_port,},
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{"int7", INT7_PORT, 0, input_port,},
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{"int8", INT8_PORT, 0, input_port,},
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{"int9", INT9_PORT, 0, input_port,},
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{"int10", INT10_PORT, 0, input_port,},
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{"int11", INT11_PORT, 0, input_port,},
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{"int12", INT12_PORT, 0, input_port,},
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{"int13", INT13_PORT, 0, input_port,},
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{"int14", INT14_PORT, 0, input_port,},
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{"int15", INT15_PORT, 0, input_port,},
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{"int16", INT16_PORT, 0, input_port,},
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{"int17", INT17_PORT, 0, input_port,},
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{"int18", INT18_PORT, 0, input_port,},
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{"int19", INT19_PORT, 0, input_port,},
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{"int20", INT20_PORT, 0, input_port,},
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{"int21", INT21_PORT, 0, input_port,},
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{"int22", INT22_PORT, 0, input_port,},
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{"int23", INT23_PORT, 0, input_port,},
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{"int24", INT24_PORT, 0, input_port,},
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{"int25", INT25_PORT, 0, input_port,},
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{"int26", INT26_PORT, 0, input_port,},
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{"int27", INT27_PORT, 0, input_port,},
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{"int28", INT28_PORT, 0, input_port,},
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{"int29", INT29_PORT, 0, input_port,},
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{"int30", INT30_PORT, 0, input_port,},
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{"int31", INT31_PORT, 0, input_port,},
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{NULL,},
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};
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/*
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* Finish off the partially created hw device. Attach our local
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* callbacks. Wire up our port names etc.
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*/
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static hw_port_event_method lm32cpu_port_event;
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static void
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lm32cpu_finish (struct hw *me)
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{
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struct lm32cpu *controller;
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controller = HW_ZALLOC (me, struct lm32cpu);
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set_hw_data (me, controller);
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set_hw_ports (me, lm32cpu_ports);
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set_hw_port_event (me, lm32cpu_port_event);
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/* Initialize the pending interrupt flags. */
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controller->event = NULL;
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}
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/* An event arrives on an interrupt port. */
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static unsigned int s_ui_ExtIntrs = 0;
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static void
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deliver_lm32cpu_interrupt (struct hw *me, void *data)
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{
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static unsigned int ip, im, im_and_ip_result;
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struct lm32cpu *controller = hw_data (me);
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SIM_DESC sd = hw_system (me);
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sim_cpu *cpu = STATE_CPU (sd, 0); /* NB: fix CPU 0. */
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address_word cia = CIA_GET (cpu);
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int interrupt = (int) data;
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HW_TRACE ((me, "interrupt-check event"));
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/*
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* Determine if an external interrupt is active
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* and needs to cause an exception.
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*/
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im = lm32bf_h_csr_get (cpu, LM32_CSR_IM);
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ip = lm32bf_h_csr_get (cpu, LM32_CSR_IP);
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im_and_ip_result = im & ip;
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if ((lm32bf_h_csr_get (cpu, LM32_CSR_IE) & 1) && (im_and_ip_result != 0))
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{
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/* Save PC in exception address register. */
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lm32bf_h_gr_set (cpu, 30, lm32bf_h_pc_get (cpu));
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/* Restart at interrupt offset in handler exception table. */
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lm32bf_h_pc_set (cpu,
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lm32bf_h_csr_get (cpu,
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LM32_CSR_EBA) +
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LM32_EID_INTERRUPT * 32);
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/* Save interrupt enable and then clear. */
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lm32bf_h_csr_set (cpu, LM32_CSR_IE, 0x2);
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}
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/* reschedule soon. */
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if (controller->event != NULL)
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hw_event_queue_deschedule (me, controller->event);
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controller->event = NULL;
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/* if there are external interrupts, schedule an interrupt-check again.
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* NOTE: THIS MAKES IT VERY INEFFICIENT. INSTEAD, TRIGGER THIS
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* CHECk_EVENT WHEN THE USER ENABLES IE OR USER MODIFIES IM REGISTERS.
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*/
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if (s_ui_ExtIntrs != 0)
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controller->event =
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hw_event_queue_schedule (me, 1, deliver_lm32cpu_interrupt, data);
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}
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/* Handle an event on one of the CPU's ports. */
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static void
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lm32cpu_port_event (struct hw *me,
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int my_port,
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struct hw *source, int source_port, int level)
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{
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struct lm32cpu *controller = hw_data (me);
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SIM_DESC sd = hw_system (me);
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sim_cpu *cpu = STATE_CPU (sd, 0); /* NB: fix CPU 0. */
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address_word cia = CIA_GET (cpu);
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HW_TRACE ((me, "interrupt event on port %d, level %d", my_port, level));
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/*
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* Activate IP if the interrupt's activated; don't do anything if
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* the interrupt's deactivated.
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*/
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if (level == 1)
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{
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/*
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* save state of external interrupt.
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*/
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s_ui_ExtIntrs |= (1 << my_port);
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/* interrupt-activated so set IP. */
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lm32bf_h_csr_set (cpu, LM32_CSR_IP,
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lm32bf_h_csr_get (cpu, LM32_CSR_IP) | (1 << my_port));
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/*
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* Since interrupt is activated, queue an immediate event
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* to check if this interrupt is serviceable.
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*/
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if (controller->event != NULL)
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hw_event_queue_deschedule (me, controller->event);
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/*
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* Queue an immediate event to check if this interrupt must be serviced;
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* this will happen after the current instruction is complete.
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*/
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controller->event = hw_event_queue_schedule (me,
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0,
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deliver_lm32cpu_interrupt,
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0);
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}
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else
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{
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/*
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* save state of external interrupt.
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*/
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s_ui_ExtIntrs &= ~(1 << my_port);
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}
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}
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const struct hw_descriptor dv_lm32cpu_descriptor[] = {
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{"lm32cpu", lm32cpu_finish,},
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{NULL},
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};
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