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-rw-r--r--firmware/zpu/lib/mdelay.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/firmware/zpu/lib/mdelay.c b/firmware/zpu/lib/mdelay.c
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index 000000000..958acf3f5
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+++ b/firmware/zpu/lib/mdelay.c
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+/* -*- c -*- */
+/*
+ * Copyright 2007 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mdelay.h"
+#include "memory_map.h"
+
+// Delay about one millisecond.
+//
+// Need 33,333 cycles at 33 MHz.
+// Each time around the loop is 10 cycles
+//
+
+#define LOOPCNT(wb_div) (MASTER_CLK_RATE/(wb_div) / 10000)
+
+inline static void
+delay_1ms(int loop_count)
+{
+/* int i;
+ for (i = 0; i < loop_count; i++){
+ asm volatile ("or r0, r0, r0\n\
+ or r0, r0, r0\n\
+ or r0, r0, r0\n\
+ or r0, r0, r0\n\
+ or r0, r0, r0\n\
+ or r0, r0, r0\n\
+ or r0, r0, r0\n");
+ }
+*/
+}
+
+// delay about ms milliseconds
+void
+mdelay(int ms)
+{
+ static int loop_count = -1;
+
+ if (hwconfig_simulation_p())
+ return;
+
+ if (loop_count < 0){
+ // set correct loop_count
+ static unsigned short lc[8] = {
+ 0,
+ LOOPCNT(1),
+ LOOPCNT(2),
+ LOOPCNT(3),
+ LOOPCNT(4),
+ LOOPCNT(5),
+ LOOPCNT(6),
+ LOOPCNT(7)
+ };
+
+ loop_count = lc[hwconfig_wishbone_divisor() & 0x7];
+ }
+
+ int i;
+ for (i = 0; i < ms; i++)
+ delay_1ms(loop_count);
+}