4 Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
6 This file is part of simavr.
8 simavr is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 simavr is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with simavr. If not, see <http://www.gnu.org/licenses/>.
27 #include "sim_interrupts.h"
30 void avr_register_vector(avr_t *avr, avr_int_vector_t * vector)
33 vector->irq.irq = vector->vector;
34 avr->vector[vector->vector] = vector;
36 printf("%s register vector %d (enabled %04x:%d)\n", __FUNCTION__, vector->vector, vector->enable.reg, vector->enable.bit);
38 if (!vector->enable.reg)
39 printf("avr_register_vector: No 'enable' bit on vector %d !\n", vector->vector);
43 int avr_has_pending_interrupts(avr_t * avr)
45 return avr->pending[0] || avr->pending[1];
48 int avr_is_interrupt_pending(avr_t * avr, avr_int_vector_t * vector)
50 return avr->pending[vector->vector >> 5] & (1 << (vector->vector & 0x1f));
53 int avr_is_interrupt_enabled(avr_t * avr, avr_int_vector_t * vector)
55 return avr_regbit_get(avr, vector->enable);
58 int avr_raise_interrupt(avr_t * avr, avr_int_vector_t * vector)
60 if (!vector || !vector->vector)
63 printf("%s raising %d (enabled %d)\n", __FUNCTION__, vector->vector, avr_regbit_get(avr, vector->enable));
64 // always mark the 'raised' flag to one, even if the interrupt is disabled
65 // this allow "pooling" for the "raised" flag, like for non-interrupt
66 // driven UART and so so. These flags are often "write one to clear"
67 if (vector->raised.reg)
68 avr_regbit_set(avr, vector->raised);
70 // Mark the interrupt as pending
71 avr->pending[vector->vector >> 5] |= (1 << (vector->vector & 0x1f));
72 avr_raise_irq(&vector->irq, 1);
74 // If the interrupt is enabled, attempt to wake the core
75 if (avr_regbit_get(avr, vector->enable)) {
76 if (!avr->pending_wait)
77 avr->pending_wait = 1; // latency on interrupts ??
78 if (avr->state != cpu_Running) {
80 printf("Waking CPU due to interrupt\n");
81 avr->state = cpu_Running; // in case we were sleeping
84 // return 'raised' even if it was already pending
88 void avr_clear_interrupt(avr_t * avr, int v)
90 avr_int_vector_t * vector = avr->vector[v];
91 avr->pending[v >> 5] &= ~(1 << (v & 0x1f));
95 printf("%s cleared %d\n", __FUNCTION__, vector->vector);
96 avr_raise_irq(&vector->irq, 0);
97 if (vector->raised.reg)
98 avr_regbit_clear(avr, vector->raised);
101 int avr_clear_interupt_if(avr_t * avr, avr_int_vector_t * vector, uint8_t old)
103 if (avr_regbit_get(avr, vector->raised)) {
104 avr_clear_interrupt(avr, vector->vector);
105 avr_regbit_clear(avr, vector->raised);
108 avr_regbit_setto(avr, vector->raised, old);
112 avr_irq_t * avr_get_interupt_irq(avr_t * avr, uint8_t v)
114 avr_int_vector_t * vector = avr->vector[v];
115 return vector ? &vector->irq : NULL;
119 * check wether interrupts are pending. I so, check if the interrupt "latency" is reached,
120 * and if so triggers the handlers and jump to the vector.
122 void avr_service_interrupts(avr_t * avr)
127 if (avr_has_pending_interrupts(avr)) {
128 if (avr->pending_wait) {
130 if (avr->pending_wait == 0) {
132 for (int bi = 0; bi < 2 && !done; bi++)
133 if (avr->pending[bi]) {
134 uint32_t map = avr->pending[bi];
136 int bit = ffs(map)-1;
137 int v = (bi * 32) + bit; // vector
138 avr_int_vector_t * vector = avr->vector[v];
139 // if that single interupt is masked, ignore it and continue
140 if (vector && !avr_regbit_get(avr, vector->enable)) {
144 if (vector && vector->trace)
145 printf("%s calling %d\n", __FUNCTION__, v);
146 _avr_push16(avr, avr->pc >> 1);
148 avr->pc = v * avr->vector_size;
150 avr_clear_interrupt(avr, v);
158 avr->pending_wait = 2; // for next one...