From c6ddfc67dd16bd197580fbead9f454031384cc5a Mon Sep 17 00:00:00 2001
From: Jacques Comeaux <jacquesrcomeaux@protonmail.com>
Date: Mon, 25 Dec 2023 01:40:53 -0600
Subject: Add blink_hex subroutine

---
 blink.s | 39 +++++++++++++++++++++++++++++++++++++--
 pll.s   | 14 ++++++++++++--
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/blink.s b/blink.s
index 62b6654..5150cab 100644
--- a/blink.s
+++ b/blink.s
@@ -29,6 +29,7 @@ setup_led:
 .global blink
 
 blink:
+  ldr r1, =SIO_BASE
   movs r0, 1
   lsls r0, 25
 1:
@@ -36,21 +37,55 @@ blink:
   bl delay_1s
   b 1b
 
+.type long_blink, %function
+.global long_blink
+
+long_blink:
+  push {lr}
+  ldr r1, =SIO_BASE
+  movs r0, 1
+  lsls r0, 25
+  bl delay_1s
+  str r0, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_1s
+  str r0, [r1, GPIO_OUT_XOR_OFST]
+  bl delay_1s
+  pop {pc}
+
 .type blinkN, %function
 .global blinkN
 
 blinkN:
   push {lr}
+  ldr r1, =SIO_BASE
   movs r2, 1
   lsls r2, 25
   tst r0, r0
   beq done
 on_then_off:
   str r2, [r1, GPIO_OUT_XOR_OFST]
-  bl delay_1s
+  bl delay_quick
   str r2, [r1, GPIO_OUT_XOR_OFST]
-  bl delay_1s
+  bl delay_quick
   subs r0, r0, 1
   bne on_then_off
 done:
   pop {pc}
+
+.type blink_hex, %function
+.global blink_hex
+
+blink_hex:
+  push {lr}
+  movs r4, r0
+  movs r5, 0xf
+1:
+  ands r0, r5
+  bl blinkN
+  lsrs r4, 4
+  beq 2f
+  bl long_blink
+  movs r0, r4
+  b 1b
+2:
+  pop {pc}
diff --git a/pll.s b/pll.s
index 38573f7..bab31f2 100644
--- a/pll.s
+++ b/pll.s
@@ -63,6 +63,16 @@ vco_lock:
 delay_1s:
   ldr r3, =0x1fca055 // 33.3 * 10^6 (one-third of a second at 100MHz)
 1: // 3 clock cycle loop
-  subs r3, r3, 1 // 1 clock cycle
+  subs r3, 1 // 1 clock cycle
   bne 1b // 2 clock cycles when taken
-  mov pc, lr
+  bx lr
+
+.type delay_quick, %function
+.global delay_quick
+
+delay_quick:
+  ldr r3, =0x65b9ab
+1:
+  subs r3, 1
+  bne 1b
+  bx lr
-- 
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