Cirrus Logic CobraNet User Manual

Page 87

CobraNet Programmer’s Reference

Management Interface Variable Reference

DS651PM25

Name

serialPPeriod

Description

Time in 256ths of a millisecond before a character received at the SCI port is placed in a packet and
transmitted. Shorter periods to achieve lower latency are appropriate for real time connections such
as MIDI. With higher settings more characters can be packed into a packet before it is transmitted
resulting in increased efficiency. Higher settings are recommended for bulk data transfer
applications.
The isochronous cycle period (1-1/3 mS) determines the minimum

serialPPeriod. Setting

serialPPeriod below the isochronous cycle rate does not further improve responsiveness. The upper
limit of responsiveness can also affected by control channel accessibility and pipeline delays. The
depth of the receive SCI character queue in combination with the baud rate determines the
maximum allowed setting. The character buffer can accommodate 100 characters. This allows for
operation at the default 10ms period at a baud rate of 57,600. At this baud rate, larger settings will
result in buffer overflow and loss of data.

Host Address

0x24002

SNMP Object ID

1.3.6.1.4.1.2680.1.1.10.1.3

Type

Integer

Attributes

Read/write - Persistent

Default Value

2560 (10ms)

Implemented Version

2.4.7 (available via SNMP in 2.6.4)

Name

serialRxMAC

Description

MAC address of the CobraNet Interface from which SCI data will be accepted. This may be any
multicast address though 01:60:2B:FD:00:00 through 01:60:2B:FD:FF:FF have been reserved by
Cirrus Logic for use as "asynchronous global channels."

ifPhysAddress is the only usable unicast

address (CobraNet does not support Ethernet promiscuous mode).

Host Address

0x24003