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Adsp-2186 – Analog Devices ADSP-2186 User Manual

Page 19

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ADSP-2186

REV. 0

–19–

Parameter

Min

Max

Unit

Bus Request/Grant

Timing Requirements:
t

BH

BR Hold after CLKOUT High

1

0.25 t

CK

+ 2

ns

t

BS

BR Setup before CLKOUT Low

1

0.25 t

CK

+ 17

ns

Switching Characteristics:
t

SD

CLKOUT High to

xMS, RD, WR Disable

0.25 t

CK

+ 10

ns

t

SDB

xMS, RD, WR Disable to BG Low

0

ns

t

SE

BG High to xMS, RD, WR Enable

0

ns

t

SEC

xMS, RD, WR Enable to CLKOUT High

0.25 t

CK

– 7

ns

t

SDBH

xMS, RD, WR Disable to BGH Low

2

0

ns

t

SEH

BGH High to xMS, RD, WR Enable

2

0

ns

NOTES
xMS = PMS, DMS, CMS, IOMS, BMS.

1

BR is an asynchronous signal. If BR meets the setup/hold requirements, it will be recognized during the current clock cycle; otherwise the signal will be recognized on

the following cycle. Refer to the ADSP-2100 Family User’s Manual for

BR/BG cycle relationships.

2

BGH is asserted when the bus is granted and the processor requires control of the bus to continue.

CLKOUT

t

SD

t

SDB

t

SE

t

SEC

t

SDBH

t

SEH

t

BS

BR

t

BH

CLKOUT

PMS

,

DMS

BMS

,

RD

WR

BG

BGH

Figure 16. Bus Request–Bus Grant