ADSP-21364SBBCZENG datasheet(25/52 Pages) AD

25 / 52 page

ADSP-21364

Preliminary Technical Data

Rev. PrB

Page 25 of 52

September 2004

Memory Read—Parallel Port

Use these specifications for asynchronous interfacing to memo-

ries (and memory-mapped peripherals) when the

ADSP-21364 is accessing external memory space.

Table 20. 8-Bit Memory Read Cycle

Parameter

Min

Max

Unit

Timing Requirements

tDRS

Address/Data 7–0 Setup Before RD High

3.3

tDRH

Address/Data 7–0 Hold After RD High

tDAD

Address 15–8 to Data Valid

D + tPCLK – 5

Switching Characteristics

tALEW

ALE Pulse Width

2 × tPCLK – 2.0

tADAS

Address/Data 15–0 Setup Before ALE Deasserted

tPCLK – 2.5

tRRH

Delay Between RD Rising Edge to Next Falling Edge.

H + tPCLK – 1

tALERW

ALE Deasserted to Read Asserted

2 × tPCLK – 2

tRWALE

Read Deasserted to ALE Asserted

F + H + 0.5

tADAH

Address/Data 15–0 Hold After ALE Deasserted

tPCLK – 0.8

tALEHZ

ALE Deasserted to Address/Data7–0 in High Z

tPCLK – 0.8

tPCLK

tRW

RD Pulse Width

D – 2

tRDDRV

RD Address Drive After Read High

F + H + tPCLK – 1

tADRH

Address/Data 15–8 Hold After RD High

D = (Data Cycle Duration = the value set by the PPDUR bits (5–1) in the PPCTL register) × tPCLK

H = tPCLK (if a hold cycle is specified, else H = 0)

F = 7 x tPCLK (if FLASH_MODE is set else F = 0)

tPCLK = (Peripheral) Clock Period = 2 × tCCLK

1 On reset, ALE is an active high cycle. However, it can be configured by software to be active low.

Figure 17. Read Cycle For 8-Bit Memory Timing

VALID ADDRESS

VALID

ADDRESS

AD15-8

ADAS

VALID ADDRESS

AD7-0

ALEW

ALE

tRW

ADAH

ADRH

DRS

DRH

DAD

ALERW

tRWALE

VALID

DATA

VALID

ADDRESS

tRDDRV

ALEHZ

VALID ADDRESS

VALID

DATA

RRH

ADSP-21364SBBCZENG Datasheet(PDF) 25 Page - Analog Devices

ADSP-21364SBBCZENG Datasheet(HTML) 25 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

Datasheet Download

Link URL