cx28560 Mindspeed Technologies, cx28560 Datasheet - Page 254

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

Buffer Controller FIFO Size Calculation
E.2
E.2.1
E-4
Key
Header Bytes (4 B)
Space for Last Bytes (4 B)
Expanding Data In
Ending a 57-Byte Message
Because the worst case scenario involves mid-range channels (to maximize amount of
data between services), examples of data expansion have only been provided for mid-
range channels.
This accumulation requires 32 bytes in the FIFO. Note the next message header and
last bytes are not accumulated because 1 byte that entered the FIFO was a FLAG from
the end of the 57-byte message. Hence, 41 data bytes entered (1 byte to finish 57-byte
message plus 40 message bytes). This is not enough for the closing flag of the 40+
byte message.
(BUFFC thinks it is still in the middle of storing the message).
56 B Mesg
Mindspeed Technologies™
Advance Information
1 B
42 B Accumulated Between Services
40 B Mesg
CX28560 Data Sheet
28560-DSH-001-B
101302_017