"QLD" encodes Core, CPM and bus maximum frequencies. "Q" means 333 Mhz core, "L" means 250 Mhz CPM, and "D" means 83 Mhz bus.
The processor has two different bus interfaces - 60x bus and local bus. 60x bus is primary bus used for main SDRAM memory connection and for connection of other devices. Local bus is separate bus for connecting SDRAM memory, directly accessible by CPM. Main core accesses this bus via 60x bus to local bus interface, while CPM can access this bus directly, so can perform a direct access even when 60x bus is busy by other transaction. Because of this advantage, local bus is used in designs, where low latency memory is mandatory, for example to store ATM connection tables, as shown in MPC8280 Reference Manual, Section 1.7 "Application Examples".
Unlike other processors, where "local bus" means bus for local memory connection, in MPC82xx family devices local bus should not be used for primary memory, 60x bus must be used.
Have a great day,
Alexander
TIC
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------
