beautypg.com

2 system power states, 2 system power states -10, Table 5-4. peripherals with pclk gating -10 – Cirrus Logic EP93xx User Manual

Page 136: Shown, Table 5-4

background image

5-10

DS785UM1

Copyright 2007 Cirrus Logic

System Controller
EP93xx User’s Guide

5

5

5

HCLK to the USB Hosts can be gated off as well to further save power. The USH_EN bit in
the

"PwrCnt"

register serves the purpose.

5.1.6.2 System Power States

The EP93xx has three power states:

•

Run mode: Normal operation mode.

•

Halt: ARM Core stops executing instructions.

•

Standby: Power is on, but only SDRAM self-refresh and the RTC run.

Figure 5-4

illustrates the transitions among power states.

Table 5-4. Peripherals with PCLK Gating

Peripheral

Peripheral/PCLK

on with Enable or

Register Access

PCLK on with

Register Access

Only

PCLK Continuous

UART1

x

-

-

UART2

x

-

-

UART3

x

-

-

KEYPAD

-

x

-

IRDA

x

-

-

SEC

x

-

-

I

2

S

x

-

-

Watchdog

-

-

x

TSC

-

x

-

PWM

x

-

-

AAC

x

-

-

SSP

x

-

-

RTC

-

-

x

GPIO

-

x

-

See also other documents in the category Cirrus Logic Hardware: