10.4.5 Resetting the CLA
There may be times when you need to reset the CLA. For example, during code debug the CLA may enter an
infinite loop due to a code bug. The CLA has two types of resets: hard and soft. Both of these resets can be
performed by the debugger or by the main CPU.
•
Hard Reset
Writing a 1 to the MCTL[HARDRESET] bit will perform a hard reset of the CLA. The behavior of a hard reset
is the same as a system reset (via XRS or the debugger). In this case all CLA configuration and execution
registers will be set to their default state and CLA execution will halt.
•
Soft Reset
Writing a 1 to the MCTL[SOFTRESET] bit performs a soft reset of the CLA. If a task is executing it will halt
and the associated MIRUN bit will be cleared. All bits within the interrupt enable (MIER) register will also be
cleared so that no new tasks start.
10.5 Pipeline
This section describes the CLA pipeline stages and presents cases where pipeline alignment must be
considered.
10.5.1 Pipeline Overview
The CLA pipeline is very similar to the C28x pipeline with eight stages:
1.
Fetch 1 (F1):
During the F1 stage the program read address is placed on the CLA program address bus.
2.
Fetch 2 (F2):
During the F2 stage the instruction is read using the CLA program data bus.
3.
Decode 1 (D1):
During D1 the instruction is decoded.
4.
Decode 2 (D2):
Generate the data read address. Changes to MAR0 and MAR1 due to post-increment using
indirect addressing takes place in the D2 phase. Conditional branch decisions are also made at this stage
based on the MSTF register flags.
5.
Read 1 (R1):
Place the data read address on the CLA data-read address bus. If a memory conflict exists,
the R1 stage will be stalled.
6.
Read 2 (R2):
Read the data value using the CLA data read data bus.
7.
Execute (EXE):
Execute the operation. Changes to MAR0 and MAR1 due to loading an immediate value or
value from memory take place in this stage.
8.
Write (W):
Place the write address and write data on the CLA write data bus. If a memory conflict exists, the
W stage will be stalled.
Control Law Accelerator (CLA)
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TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Summary of Contents for TMS320 2806 Series
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