LPC-H3131: SDRAM comments updated

2013-11-21 14:47:37 -06:00 · 2013-11-21 14:47:37 -06:00 · c282733058
parent 37591022ca
commit c282733058
1 changed files with 4 additions and 2 deletions
--- a/configs/olimex-lpc-h3131/src/lpc31_mem.c
+++ b/configs/olimex-lpc-h3131/src/lpc31_mem.c
@ -109,8 +109,10 @@

 static uint32_t lpc31_ns2clk(uint32_t ns, uint32_t hclk2)
 {
- /* Example: ns=80, hclk2=90000000
-  * clocks = 80 * 90000000 / 1000000000 + 1 = 8
+ /* delay (ns) * hclk (Hz) / scale (ns/sec) = cycles
+  *
+  * Example: ns=80, hclk2=90000000
+  * clocks = 80 * 90000000 / 1000000000 + 1 = 8 (actual 7.2 cycles)
  */

  uint64_t tmp = (uint64_t)ns * (uint64_t)hclk2 / 1000000000ull;