rp2040

commit f240214eb07a70a1828e94011c90ef4112e13877
parent 9d89be5ee9e205aceb5d1455db0c4a484c2c3057
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Thu, 27 Apr 2023 10:37:19 +0900

setup xosc

Diffstat:
M
ex2/main.s
 | 
12
+++++++++++-

1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/ex2/main.s b/ex2/main.s
@@ -35,7 +35,15 @@ unreset_chk:
 	str r0, [r3, #0x24] // SIO: GPIO_OE
 
 	// setup xosc
-
+	ldr r3, xosc_base
+	mov r0, #47 // start up delay for 12MHz xosc
+	str r0, [r3, #0xc] // XOSC: STARTUP
+	ldr r0, =(0xfab << 12 | 0xaa0)
+	str r0, [r3, #0] // XOSC: CTRL
+wait_xosc:
+	ldr r0, [r3, #0x4] // XOSC: STATUS
+	lsr r0, r0, #31 // STABLE bit
+	beq wait_xosc
 
 	// blink led on gpio25
 loop:
@@ -110,5 +118,7 @@ resets_base:
 	.word 0x4000c000
 io_bank0_base:
 	.word 0x40014000
+xosc_base:
+	.word 0x40024000
 sio_base:
 	.word 0xd0000000