rp2040

commit 181ef24e87dc72c878c65494a07c284daf688276
parent 6937c573588a9180fe75267f5fb64a676585ab46
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Wed, 28 Feb 2024 07:38:24 +0900

count clock cycles
they are not affected by RUN button

Diffstat:
M
ex3/main.s
 | 
22
+++++++++++++++-------

1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/ex3/main.s b/ex3/main.s
@@ -127,19 +127,27 @@ wait_vco:
 	// set timer
 	ldr r0, =0x20000 // 
 	bl set_alarm
-/*
+
 	// debug: count frequency
 	ldr r3, clocks_base
+	add r3, r3, #0x80
 wait_fc0:
-	ldr r0, [r3, #0x98] // CLOCKS: FC0_STATUS
+	ldr r0, [r3, #0x18] // CLOCKS: FC0_STATUS
 	ldr r1, =(1 << 8) // RUNNING
 	tst r0, r1
-	beq wait_fc0
+	bne wait_fc0
 	ldr r0, =(12 * 1000) // 12MHz
-	str r0, [r3, #0x80] // CLOCKS: FC0_REF_KHZ
-	mov r0, #0x09 // clk_sys
-	str r0, [r3, #0x94]
-*/
+	str r0, [r3, #0] // CLOCKS: FC0_REF_KHZ
+	mov r0, #0x0a // clk_peri
+	str r0, [r3, #0x14] // CLOCKS: FC0_SRC
+wait_fc1:
+	ldr r0, [r3, #0x18] // CLOCKS: FC0_STATUS
+	ldr r1, =(1 << 4) // DONE
+	tst r0, r1
+	beq wait_fc1
+	ldr r0, [r3, #0x1c] // CLOCKS: FC0_RESULT
+	bl printh
+
 loop:
 	ldr r0, =0xdeadcafe
 	bl printh