Alisa Allaire / Mbed 2 deprecated 4180L1_P1ASM

s

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Revision 0:208fc50f22f9, committed 2018-01-18

Comitter:
aallaire3
Date:
Thu Jan 18 18:13:24 2018 +0000
Commit message:
shshss

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
my_asm.s Show annotated file Show diff for this revision Revisions of this file 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jan 18 18:13:24 2018 +0000
@@ -0,0 +1,10 @@
+#include "mbed.h"
+
+extern "C" int my_asm();
+
+int main() {
+
+    while(1) {
+        my_asm();         
+    }
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Jan 18 18:13:24 2018 +0000
@@ -0,0 +1,1 @@
+https://mbed.org/users/mbed_official/code/mbed/builds/64910690c574
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/my_asm.s	Thu Jan 18 18:13:24 2018 +0000
@@ -0,0 +1,20 @@
+  AREA asm_func, CODE, READONLY
+  EXPORT my_asm
+
+my_asm
+
+  LDR R1, =0x2009C000 // pushbutton at p8
+  LDR R2, =0x2009C040 // led at p21
+
+  MOV.W R3, #0x000020   ; 0x000020 = 1<<5 all "0"s with a "1" in bit 5
+; value passed from C compiler code is in R0 - compare to a "0" 
+  CMP R1, #0          ; value == 0 ?
+; (If-Then-Else) on next two instructions using equal cond from the zero flag
+  ITE EQ
+; STORE if EQ - clear led 1 port bit using GPIO FIOCLR register and mask
+  STREQ R3, [R2,#0x5C]  ; if==0, clear LED1 bit
+; STORE if NE - set led 1 port bit using GPIO FIOSET register and mask
+  STRNE R3, [R1,#0x58]  ; if==1, set LED1 bit
+; Return to C using link register (Branch indirect using LR - a return)
+  BX LR
+  END
\ No newline at end of file