dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 239

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

Chapter 8
Program Controller
The program controller is perhaps the most important unit in the DSP56800E core. It fetches and decodes
instructions, coordinates the other core units in executing the instructions, and directs program flow,
including exception processing. It also contains dedicated circuitry to accelerate looping operations.
This chapter describes the program controller’s function, including details on stack handling and
no-overhead hardware looping. The different processing states, including reset and exception processing,
are covered in Chapter 9, “Processing States.” For more in-depth information on the execution pipeline,
see Chapter 10, “Instruction Pipeline.”
8.1
A block diagram of the program controller is given in Figure 8-1 on page 8-2. As the figure shows, the
following major blocks are located within the program controller:
The blocks and registers within the program controller are explained in the following sections.
Freescale Semiconductor
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Instruction latch and decoder
Program counter (PC)
Hardware stack
Looping control unit
Interrupt control unit
Program Controller Architecture
Program Controller
8-1