SMC Networks PL241 Network Card User Manual


 
Functional Overview
ARM DDI 0389B Copyright © 2006 ARM Limited. All rights reserved. 2-15
2.4 SMC 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.
2.4.1 Operating states
The operation of the SMC is based on three operating states. In this section, each state
is described. Figure 2-10 shows the state machine.
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-power The 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.
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