rp2040

commit 8339cebb8f88c8d33f83a2f8baa423691716ffe2
parent d631538bf79ac256e65bfa9b3e1f8432aa03303a
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Thu,  6 Apr 2023 08:46:42 +0900

test rxd-fifo

Diffstat:
M
boot2/boot2.S
 | 
11
++++++++++-

1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/boot2/boot2.S b/boot2/boot2.S
@@ -91,7 +91,16 @@ wait_sreg:
 	str r1, [r4, #0x60] // SSI: DR0
 	bl wait_ssi
 	// I think I need to read rxd-fifo
-	// ldr r1, [r4, #0x60]
+	ldr r1, [r4, #0x60]
+/*
+// this loop is for test if the rxd-fifo is empty.
+// the fifo is not empty without the ldr instruction above.
+loop:
+	ldr r1, [r4, #0x28] // SSI: SR
+	mov r2, #8 // RFNE
+	tst r1, r2
+	bne loop
+*/
 
 	// set SIP continuous read
 	// disable ssi