Asynchronous Rates; Slew Rate And Cable Length; Ethernet - Sun Microsystems Sun Blade 1000 Service Manual

C.1.13.5

Asynchronous Rates

The serial asynchronous ports support twenty baud rates that are all exact divisors
of the crystal frequency (with the exception of 110, which is off by less than 1
percent). Baud rates include 50, 75, 110, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
19200, 38400, 57600, 76800, 115200, 153600, 230400, 307200, and 460800.
C.1.13.6

Slew Rate and Cable Length

The maximum RS-423 cable length is 118 feet (30 meters) and the maximum RS-232
cable length is 50 feet (15.24 meters). The slew rate changes depending on the speed.
For speeds less than 100 Kbaud, the slew rate is set at 5 VDC per microsecond. For
rates greater than 100 Kbaud, the slew rate is increased to 10 VDC per microsecond.
This allows maximum performance for the greater baud rates and better signal
quality at the lesser baud rates.
C.1.14

Ethernet

The workstation supports 10-Mbps, 10BASE-T, twisted-pair Ethernet; and 100-Mbps,
100BASE-T. Twisted-pair Ethernet is provided through an 8-pin RJ45 connector. The
Ethernet circuitry design is based on a Lucent PHY.
The PHY chip integrates a 100BASE-T physical coding sub-layer (PCS) and a
complete 10BASE-T module in a single chip.
The 100BASE-X portion of the PHY IC consists of the following functional blocks:
Transmitter
Receiver
Clock generation module
Clock recovery module
The 10BASE-T section of the PHY IC consists of the 10-Mbps transceiver module
with filters.
The 100BASE-X and 10BASE-T sections share the following functional
characteristics:
PCS control
IEEE 802.3u auto negotiation
C-36 Sun Blade 1000 and Sun Blade 2000 Service Manual • January 2002