Warm Reset Flow

Figure 7–3 Sleep Mode Sequence of Operation

internal clks

state

SLEEP IPR Wake-up interrupt

SromOE_L

ClkFwdRst_H

TestStat_H

 

 

 

 

 

 

b

 

f

 

RUN

DOWN1

DOWN2

DOWN3 WAIT_INTR

RAMP1

RAMP2

WAIT_ClkFwdRst0

 

WAIT_BiSI WAIT_ClkFwdRst1

RUN

 

 

 

 

 

 

a

c

e

 

 

 

 

 

 

 

 

 

 

no min

no min

A

d

internal ClkFwdRst

external Clks

FM-06487A.AI4

Table 7–7describes each signal and constraint for the sleep mode sequence.

Table 7–7 Signals and Constraints for the Sleep Mode Sequence

Signal Name

Description

Constraint

 

 

 

ClkFwdRst_H

Signal asserted by the system to

 

initialize and reset clock forwarding

 

interfaces

Forwarded clocks

Bit clocks forwarded to/from the

 

21264/EV67

System interrupt

Asynchronous interrupt which

 

causes the 21264/EV67 to exit sleep

 

mode

ClkFwdRst_H must be asserted by the system when entering sleep mode. The system deasserts ClkFwdRst_H no sooner than one FrameClk_H cycle after sourcing an interrupt to the 21264/ EV67.

Clocks stop running under ClkFwdRst_H.

7.4 Warm Reset Flow

The warm reset sequence of operation is triggered by the assertion of the Reset_L sig- nal line. The reset state machine is initially in RUN state. The 21264/EV67 then, by default, ramps down the PLL (similar to the sleep flow sequence) and the reset state machine ends up in the WAIT_RESET state.

Note the effects of entry into that state on the IPRs listed in Table 7–8 .

Table 7–8 Effect on IPRs After Warm Reset

IPR

Effects After Warm Reset

PAL_BASE

Cleared

I_CTL

Cleared

PCTX[FPE]

Set

WRITE_MANY

Cleared (That is, the WRITE_MANY chain is initialized and the Bcache is

 

turned off.)

 

 

Alpha 21264/EV67 Hardware Reference Manual

Initialization and Configuration 7–11

Page 219
Image 219
Compaq 21264, EV67 Warm Reset Flow, Signals and Constraints for the Sleep Mode Sequence, Effect on IPRs After Warm Reset