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| author | Joel Sherrill <joel.sherrill@oarcorp.com> | 2013-07-09 11:15:57 -0500 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@oarcorp.com> | 2013-07-09 12:40:51 -0500 |
| commit | 48a22edb4ae2ef41969095abc5a514910361ee58 (patch) | |
| tree | a93db9739cdda6bfd823db9a9be6f8d2b6e71c0a | |
| parent | threadhandler.c: Add comments (diff) | |
| download | rtems-48a22edb4ae2ef41969095abc5a514910361ee58.tar.bz2 | |
libchip ns16550.c: Improve comment
| -rw-r--r-- | 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 de2245651f..829284a86c 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); |