28478G-18 Mindspeed Technologies, 28478G-18 Datasheet - Page 148

• Manufacturer Part Number: 28478G-18
• Description: Multichannel Synchronous Communications Controller 208-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of 28478G-18

• Package: 208BGA
• Maximum Data Rate: 32768 Kbps
• Transmission Media Type: Wire
• Power Supply Type: Analog
• Typical Supply Current: 250 mA
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3 V
• Maximum Operating Supply Voltage: 3.6 V

6.4.5.1
The Idle Code (IC) specification allows an idle code to be transmitted after the current message in case the next
message is not available to be transmitted or inter-message pad fill is requested via PADEN.
6.4.5.2
The Pad Enable (PADEN) and Pad Count (PADCNT) specifications allow pad fill octets (a sequence of one or more
specified idle codes) to be transmitted between messages. PADEN enables or disables the pad fill octet
transmission feature. PADCNT is the minimum number of fill octets to be transmitted between the closing flag of
one message and the opening flag of the next message.
6.4.5.3
The Repeat Message Transmission (REPEAT) specification allows a single message to be transmitted repeatedly
without additional host intervention. This feature is required to support SS7 message retransmission. In the SS7
application, a retransmitted message is usually 3, 4, or 5 octets in length. Message retransmission in MUSYCC
requires that the entire message be held in a single shared memory message buffer, versus being spread across
multiple buffers. The message retransmission feature is not limited to SS7 applications.
6.4.6
The message configuration bits described above are used in special data communication applications requiring the
following attributes specified on a per-message basis:
•
•
•
If at least one transmit channel in a channel group is supporting an application which requires any one of the above
attributes, the Message Configuration Bits Copy must be enabled for the entire channel group by setting the
MCENBL bit field to 1.
Setting MCENBL to 0 prevents MUSYCC from copying the Message Configuration Bits from the Transmit Buffer
Descriptor and has the following effect on transmit channel operations throughout the channel group:
•
•
Any of the Message Configuration Bits can be changed by writing new values for these bit fields directly into a
channel group’s Transmit Configuration Table. However, the exact time the new bit field values are applied by the
transmitter is unrelated to the message being serviced. If the channel is idle, any change to the message
configuration bits in the Configuration Table will apply to subsequent messages.
To write new configuration bits into the Transmit Message Configuration Table, a PCI dword operation is required.
Tables 6-12
28478-DSH-002-E
Specific idle code is to be transmitted between messages.
Inter-message pad fill is required.
Repeat message transmission is required.
PADEN and PADCNT are set to 0, thereby facilitating back-to-back message transmission.
REPEAT is set to 0, thereby disabling automatic message retransmission.
and
6-13
Idle Code
Inter-message Pad Fill
Repeat Message Transmission
Message Configuration Bits Copy Enable/Disable
list the address map and the Message Configuration Descriptor layouts.
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