diff options
Diffstat (limited to 'dmascc/README.dmascc')
| -rw-r--r-- | dmascc/README.dmascc | 63 |
1 files changed, 45 insertions, 18 deletions
diff --git a/dmascc/README.dmascc b/dmascc/README.dmascc index fcd7746..1945616 100644 --- a/dmascc/README.dmascc +++ b/dmascc/README.dmascc @@ -1,3 +1,5 @@ +$Id: README.dmascc,v 1.2 2001/05/10 10:44:45 csmall Exp $ + The dmascc_cfg utility ====================== @@ -14,18 +16,19 @@ Options: --show Show all configurable parameters for this port. May be specified at any time by any user. -All other options change parameters and thus may only be specified - - by root - - when the interface is down +All other options change parameters and thus may only be specified by root +and only when the interface is down. + +f ... floating-point argument, i ... integer argument. ---speed <f> Set frequency of baud rate generator. A value of 0 disables +--frequency f Set frequency of baud rate generator. A value of 0 disables the baud rate generator and the digital PLL. Use the --show option to check whether the frequency you selected could be approximated with sufficient accuracy. --nrzi 0 | 1 0 selects NRZ mode, 1 selects NRZI mode. ---clocks <i> Set clock mode. You may OR together three choices (other +--clocks i Set clock mode. You may OR together three choices (other values are not supported and may cause strange results): TX clock pin: 0x00 input @@ -45,25 +48,49 @@ All other options change parameters and thus may only be specified * Not allowed on PI2 Port A if J3 is installed. # TX clock pin must be configured as input - + Speed must be equal to 32 times the baud rate. + + The BRG frequency must be equal to 32 times the baud rate. + +--txdelay f Set the transmit delay (in ms). + +--txpause f Set the delay (in ms) between two transmitted packets. + This parameter sometimes helps to reduce RX FIFO overruns, + if the receiving station has a slower CPU than the + transmitting station and cannot re-initialize the SCC's + receiver quickly enough. ---txdelay <f> Set transmit delay in ms (0 < f < 2500). +--txtimeout f Set the time (in ms), after which the transmitter may + not squeeze in another packet, but rather has to go + off-air. ---txtime <f> Set maximum time in s the transmitter may be active - (0 < f). +--txtail f Set the time (in ms) between the end of the last packet + and the RTS line actually going inactive. ---sqdelay <f> Set squelch delay in ms (0 < f < 2500). +--rtsoff f Set the DCD settling time (in ms) after switching off the + transmitter. During this period the DCD line is being + ignored. This parameter is especially useful for the + S5SCC/DMA, which frequently generates short DCD pulses + after switching from TX to RX. ---slottime <f> Set slot time in ms (0 < f < 2500). +--dcdon f Set the DCD settling time (in ms) after the DCD line has + become active. This parameter should be < txdelay. ---waittime <f> Set the minimum time in ms between transmitter off and - transmitter on (0 < f < 2500). +--dcdoff f Set the DCD settling time (in ms) after the DCD line has + become inactive. This parameter should be >= rtsoff. ---persist <i> Set persistence parameter (0 <= i <= 255). +--slottime f Set the slot time (in ms). ---dma <i> Set DMA channel (0, 1, or 3). 0 disables DMA. +--persist i Set the persistence parameter (1 <= i <= 256). After the + DCD off settling time has expired, the driver waits + random(0..255)/persist*slottime before activating the + RTS line. Integer arithmetic is being performed; + persist==256 thus means zero delay in any case (which only + makes sense in a two-station scenario). -<f> ... floating-point argument, <i> ... integer argument. -Parameters are not checked for validity. The driver or the kernel may crash -if you specify invalid values. +--waittime f Set the minimum time (in ms) before a station may start + transmitting again (after the RTS off settling time has + expired). This value should be larger than + 255/persist*slottime. +--dma i Set the DMA channel (-1, 0, 1, or 3). -1 disables DMA. + 0 is only valid on the S5SCC/DMA. Remember, DMA can be + used only on channel A (dmascc0, dmascc2, and so on). |