[rtems commit] libchip ns16550.c: Improve comment
Joel Sherrill
joel at rtems.org
Tue Jul 9 17:35:03 UTC 2013
Module: rtems
Branch: master
Commit: 48a22edb4ae2ef41969095abc5a514910361ee58
Changeset: http://git.rtems.org/rtems/commit/?id=48a22edb4ae2ef41969095abc5a514910361ee58
Author: Joel Sherrill <joel.sherrill at oarcorp.com>
Date: Tue Jul 9 11:15:57 2013 -0500
libchip ns16550.c: Improve comment
---
c/src/libchip/serial/ns16550.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/c/src/libchip/serial/ns16550.c b/c/src/libchip/serial/ns16550.c
index de22456..829284a 100644
--- a/c/src/libchip/serial/ns16550.c
+++ b/c/src/libchip/serial/ns16550.c
@@ -501,10 +501,13 @@ int ns16550_set_attributes(
/*
* Set the baud rate
+ *
+ * NOTE: When the Divisor Latch Access Bit (DLAB) is set to 1,
+ * the transmit buffer and interrupt enable registers
+ * turn into the LSB and MSB divisor latch registers.
*/
(*setReg)(pNS16550, NS16550_LINE_CONTROL, SP_LINE_DLAB);
- /* XXX are these registers right? */
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, ulBaudDivisor&0xff);
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, (ulBaudDivisor>>8)&0xff);
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