cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 228

• Manufacturer Part Number: cx28560
• Description: Hdlc Controller
• Manufacturer: Mindspeed Technologies

Flexiframe Algorithm
B.5.1
B.5.2
B-10
Equations for Analysis
Solution for Equations
To prove that a 21,504 Flexiframe is a sufficient number of slots for any legal
configuration of the CX28560, it is necessary to state the rules of a legal configuration
and to express them mathematically:
Note that for each range the number of channels in the range is multiplied by the
lower limit of the range because this limit is the worst case.
The number of slots in the frame is equal or less then the frame size – 21504:
1024 * a + 512 * (b + c) + 256 * (b + d + e) + 128 * (d + f + g) + 64 *
(f + h + i) + 32 * (h + j + k) + 16 * (j + l + m) + 8 * (l + n + o) + 4 *
(n + p + q) + 2 * (p + r + s) + 1 * r <= 21504
Equations (a) and (b) were entered into linear-programming problem solving software
together with a command to find the maximum value of equation (c) under the
constraints of (a) and (b).
The maximum value of the last equation found was 20,899. Hence, a 21,504 is large
enough to encompass the required slot assignment for any configuration of channel
bit rates that conforms to the first 2 equations (less than 2028 channels, and aggregate
bit rate less than or equal to 700 Mbps).
a.
b.
The number of channels is equal or less than 2047:
a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p + q + r + s
< 2048
The maximum bandwidth that can enter the CX28560 is 700 Mbps:
39 * a + 26 * b + 19.5 * c + 13 * d + 9.75 * e + 6.5 * f + 4.875 *
g + 3.25 * h + 2.438 * i + 1.625 * j + 1.219 * k + 0.813 * l + 0.609 *
m + 0.406 * n + 0.304 * o + 0.203 * p + 0.152 * q + 0.101 * r + 0.064 * s <=
700
Mindspeed Technologies™
Advance Information
CX28560 Data Sheet
28560-DSH-001-B