28478G-18 Mindspeed Technologies, 28478G-18 Datasheet - Page 88

• 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

Table 5-4.
The Group Base Pointer value is written into MUSYCC by the host via PCI write access cycles. The location of the
Group Base Pointer register for each group within MUSYCC is listed in
For this illustration, the host must perform the following write operations, as listed in
Table 5-5.
Next, the host allocates the required shared memory for transmit and receive messages. Assume, for example, the
host needs 8 message descriptors for each channel and direction, and each corresponding data buffer per
message is 100h (256) bytes in length.
28478-DSH-002-E
Group 0 Base Pointer
Group 1 Base Pointer
Group 2 Base Pointer
Group 3 Base Pointer
Group 4 Base Pointer
Group 5 Base Pointer
Group 6 Base Pointer
Group 7 Base Pointer
Channel Group Descriptors
Memory for Message Descriptors =
32 channels/group *
2 directions/channel *
12 bytes/message descriptor *
8 buffers/channel
= 1800h bytes/group
= 6144 bytes/group
Shared Memory Allocation
Host Assigns Group Base Pointers
Host Writes Pointer Value
Preliminary Information / Mindspeed Proprietary and Confidential
0090 0000h
0090 0800h
0090 1000h
0090 1800h
0090 2000h
0090 2800h
0090 3000h
0090 3800h
Mindspeed Technologies
—
Start Address
0090 0800h
0090 2800h
0090 0000h
0090 1000h
0090 1800h
0090 2000h
0090 3000h
0090 3800h
Group Descriptors
®
End Address
0090 061Ch
0090 0E1Ch
0090 161Ch
0090 1E1Ch
0090 261Ch
0090 2E1Ch
0090 361Ch
0090 3E1Ch
Table
5-1.
Table
To PCI Address
0240 0000h
0240 0800h
0240 1000h
0240 2000h
0240 2800h
0240 3000h
02401800h
02403800h
Memory Organization
5-5.
1,564 bytes
1,564 bytes
1,564 bytes
1,564 bytes
1,564 bytes
1,564 bytes
1,564 bytes
1,564 bytes
Length
75