Cirrus-logic CS8900A Instrukcja Użytkownika Pobierz pdf (Strona 28)

28 DS271F5

CS8900A

Crystal LAN™ Ethernet Controller

CIRRUS LOGIC PRODUCT DATASHEET

8). To exit SW Suspend, the host must write to

the CS8900A’s assigned I/O space (the Write

is only used to wake the CS8900A, the Write

itself is ignored). Upon exit, the CS8900A per-

forms a complete reset, and then goes through

a normal initialization procedure.

Any hardware reset takes the chip out of any

sleep mode.

Table 9 summarizes the operation of the three

low-power modes.

CS8900A Configuration CS8900A Operation

SLEEP

(Pin 77)

HWStandbyE

(SelfCTL, Bit A)

HWSleepE

(SelfCTL, Bit 9)

SWSuspend

(SelfCTL, Bit 8) Link Activity

Low 1 1 N/A Not Present HW Standby mode: 10BASE-T

receiver listens for link activity

Low 1 1 N/A Present HW Standby mode: LANLED

low

Low 0 1 N/A N/A HW Suspend mode

Low to

High

N/A 1 0 N/A CS8900A resets and goes through

initialization

High N/A N/A 0 N/A Not in low-power mode

High N/A N/A N/A SW Suspend mode

Low N/A 0 1 N/A SW Suspend mode

Low N/A 0 0 N/A Not in low-power mode

Notes: 1. Both HW and HW Suspend take precedence over SW Suspend.

Table 9. Low-Power Mode Operation

1 2 ... 23 24 25 26 27 28 29 30 31 32 33 ... 137 138

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Cirrus-logic CS8900A Instrukcja Użytkownika Strona 28