SMC Networks AHB SRAM/NOR SMC functional operation, Operating states Clocking and resets on page

Models: AHB SRAM/NOR PL241

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2.4SMC functional operation

Functional Overview

2.4SMC functional operation

This section describes:

Operating states

Clocking and resets on page 2-16

Miscellaneous signals on page 2-18

APB slave interface operation on page 2-19

Format block on page 2-19

Memory manager operation on page 2-22

Interrupts operation on page 2-27

Memory interface operation on page 2-27.

2.4.1Operating states

The operation of the SMC is based on three operating states. In this section, each state is described. Figure 2-10shows the state machine.

5HVHW

5HDG\

/RZSRZHU •Operating states

Figure 2-10 SMC aclk domain FSM

The SMC states are as follows:

Reset
Power is applied to the device, and hresetn is held LOW.

Ready Normal operation of the device. You can access the SMC register bank through the AHB configuration port and external memory devices accessed through the SMC interface.

Low-powerThe device does not accept new AHB transfers, and only certain registers are accessible through the APB interface. You can stop the SMC clocks to reduce power consumption.

ARM DDI 0389B

Copyright © 2006 ARM Limited. All rights reserved.

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SMC Networks AHB SRAM/NOR, PL241 manual SMC functional operation, Operating states Clocking and resets on page, Reset