Compaq specifications 11 21264/EV68A Reset State Machine State Descriptions

Models: EV68A

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Reset State Machine

Figure 7–5 21264/EV68A Reset State Machine State Diagram

 

 

PLL Ramp Up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset_L

 

 

RAMP1

Counter

 

 

 

 

 

 

 

 

 

deasserted

 

[2,4]

finished

 

 

 

 

 

 

DCOK_H

 

WAIT_

 

 

 

 

 

RAMP2

Counter

 

 

 

NOMINAL

 

 

 

 

 

 

 

asserted

 

 

 

 

 

 

[1,2]

finished

 

 

[16,32]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WAIT_

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SETTLE

 

 

 

 

 

 

 

 

 

 

 

WAIT_ClkFwd

 

[16,32]

 

 

 

 

 

 

 

 

 

 

 

Rst0

 

 

 

 

 

 

 

 

 

 

Counter

ClkFwdRst_H

 

 

Out of

 

 

 

 

 

 

 

 

 

finished

 

 

 

Reset_L

 

 

 

 

Reset_L

 

deasserted

 

 

 

Sleep

 

 

 

 

 

 

 

 

 

 

asserted

 

 

 

 

deasserted

 

 

 

 

 

 

Mode

COLD

 

Enabled

 

 

 

 

 

 

 

 

Out of

 

 

 

 

 

 

 

 

 

 

FAULT_

 

Interrupt

 

 

 

 

 

WAIT_

WAIT_

 

 

 

 

 

 

 

RESET*

 

 

 

 

 

 

 

 

 

 

BiST

BiSI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset_L

 

 

 

 

 

 

FAULT_

 

BiST

 

 

BiSI

 

 

 

 

 

 

 

 

RESET

 

 

 

WAIT_

asserted

 

WAIT_

 

 

 

 

 

 

finished

 

 

finished

 

 

 

 

RESET

 

 

 

 

 

 

 

 

 

 

 

INTERRUPT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ClkFwdRst_H

 

 

 

 

 

 

 

 

 

 

 

 

 

asserted

WAIT_ClkFwd

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Numbers in "[,]" are

 

 

 

Rst1

 

 

 

 

 

 

 

 

Xdiv and Zdiv divisors,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

respectively

 

 

 

 

 

 

Counter

 

 

Counter

 

 

 

 

*No BiST/BiSI

 

 

ClkFwdRst_H

finished &

 

 

finished &

 

 

 

on recovery from Fault

deasserted

Sleep Mode

 

 

not Sleep Mode

 

 

 

 

Reset

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PLL Ramp Down

 

 

 

 

RUN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Counter

 

 

 

Counter

 

 

 

 

 

 

 

 

DOWN3

 

finished

DOWN2

finished

DOWN1

Sleep Mode

 

 

 

 

 

 

 

 

 

 

[16,32]

 

 

 

[2,4]

 

 

[1,2]

or Reset_L

 

asserted

LKG-10982A-98WF

Table 7–11 21264/EV68A Reset State Machine State Descriptions

State Name

Description

 

 

COLD

Chip cold. Transitioned to WAIT_SETTLE with assertion of Reset_L, PLL_VDD, and

 

VDD.

WAIT_SETTLE

PLL_VDD asserted; PLL at minimum frequency.

WAIT_NOMINAL

Triggered by assertion of DCOK_H. PLL achieves a lock at Xdiv and Zdiv divisors equal

 

16 and 32, respectively.

RAMP1

Triggered by Reset_L deassertion; Xdiv and Zdiv divisors are changed to 2 and 4, respec-

 

tively, increasing the internal GCLK frequency. An internal duration counter is initial-

 

ized to count 4108 GCLK cycles.

21264/EV68A Hardware Reference Manual

Initialization and Configuration 7–17

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Compaq specifications 11 21264/EV68A Reset State Machine State Descriptions