X-Git-Url: https://oss.titaniummirror.com/gitweb/?a=blobdiff_plain;f=doc%2Ftxt%2Ftep113.txt;h=bd7de8efe9110479f6766270a915f4ce0f0c157b;hb=2c0e71d50b57d3194611948f14645e5df2a6bc43;hp=a251db7dc5a3f241d8e62a4c1b0467a6352f1877;hpb=80cfb0a4f848228be947dab0b14af67e07f085ad;p=tinyos-2.x.git diff --git a/doc/txt/tep113.txt b/doc/txt/tep113.txt index a251db7d..bd7de8ef 100644 --- a/doc/txt/tep113.txt +++ b/doc/txt/tep113.txt @@ -280,22 +280,22 @@ actively sending an acknowledgement. Only the PC-to-mote communication path supports acknowledgements. SerialP does not request acknowledgements from the PC for two reasons. -First, acks are not perfect reliability: they are used on the PC-to-mote -path to raise reliability to a usable level. In the case of the PC-to-mote -path, the UART receive buffer is typically a single byte, so a high interrupt -load can easily lose (and sometimes does) a byte. This is in contrast -to the PC receive buffer, which is much larger and does not have to -deal with overflow. Second, adding support for acks would increase -the code size and complexity of the serial stack. As code space is -often at a premium, this would add little needed functionality at significant -cost. Of course, any application that -requires perfect reliability may layer its own scheme on top of the -serial protocol. +First, acks are not perfect reliable: they are used on the +PC-to-mote path to raise reliability to a usable level. In the case of +the PC-to-mote path, the UART receive buffer is typically a single +byte, so a high interrupt load can easily lose (and sometimes does) a +byte. This is in contrast to the PC receive buffer, which is much +larger and does not have to deal with overflow. Second, adding support +for acks would increase the code size and complexity of the serial +stack. As code space is often at a premium, this would add little +needed functionality at significant cost. Of course, any application +that requires perfect reliability may layer its own scheme on top of +the serial protocol. The acknowledgement protocol is stop-and-wait to minimize buffering on the mote side. This is considered more important on memory constrained devices than increased throughput in the PC-to-mote direction, which -most applications only use for occasional contro transmissions. +most applications only use for occasional control transmissions. 3.4 Dispatcher: SerialDispatcherC