TMS44400, TMS44400P, TMS46400, TMS46400P

1048576-WORD BY 4-BIT

DYNAMIC RANDOM-ACCESS MEMORIES

SMHS562C – MAY 1995 – REVISED NOVEMBER 1996

9

POST OFFICE BOX 1443

timing requirements over recommended ranges of supply voltage and operating free-air

temperature

’4x400 - 60

’4x400P - 60

’4x400 - 70

’4x400P - 70

’4x6400 - 80

’4x400P - 80

UNIT

MIN

MAX

MIN

MAX

MIN

MAX

tRC

Cycle time, random read or write (see Note 8)

110

130

150

ns

tRWC

Cycle time, read-write

155

181

205

ns

tPC

Cycle time, page-mode read or write (see Note 9)

40

45

50

ns

tPRWC

Cycle time, page-mode read-write

85

96

105

ns

tRASP

Pulse duration, RAS low, page mode (see Note 10)

60

100 000

70

100 000

80

100 000

ns

tRAS

Pulse duration, RAS low, nonpage mode (see Note 10)

60

10 000

70

10 000

80

10 000

ns

tRASS

Pulse duration, RAS low, self refresh

100

100

100

µs

tCAS

Pulse duration, CAS low (see Note 11)

10

10 000

18

10 000

20

10 000

ns

tCP

Pulse duration, CAS high

10

10

10

ns

tRP

Pulse duration, RAS high (precharge)

40

50

60

ns

tRPS

Precharge time after self refresh using RAS

110

130

150

ns

tWP

Pulse duration, write

10

10

10

ns

tASC

Setup time, column address before CAS low

0

0

0

ns

tASR

Setup time, row address before RAS low

0

0

0

ns

tDS

Setup time, data (see Note 12)

0

0

0

ns

tRCS

Setup time, W high before CAS low

0

0

0

ns

tCWL

Setup time, W low before CAS high

15

18

20

ns

tRWL

Setup time, W low before RAS high

15

18

20

ns

tWCS

Setup time, W low before CAS low (early-write operation only)

0

0

0

ns

tWSR

Setup time, W high (CBR refresh only)

10

10

10

ns

tWTS

Setup time, W low (test mode only)

10

10

10

ns

tCAH

Hold time, column address after CAS low

10

15

15

ns

tDHR

Hold time, data after RAS low (see Note 13)

50

55

60

ns

tDH

Hold time, data (see Note 12)

10

15

15

ns

tAR

Hold time, column address after RAS low (see Note 13)

50

55

60

ns

tRAH

Hold time, row address after RAS low

10

10

10

ns

tRCH

Hold time, W high after CAS high (see Note 14)

0

0

0

ns

tRRH

Hold time, W high after RAS high (see Note 14)

0

0

0

ns

tWCH

Hold time, W low after CAS low (early-write operation only)

10

15

15

ns

tWCR

Hold time, W low after RAS low (see Note 13)

50

55

60

ns

tWHR

Hold time, W high (CBR refresh only)

10

10

10

ns

tWTH

Hold time, W low (test mode only)

10

10

10

ns

tCHS

Hold time, CAS low after RAS high (self refresh)

– 50

– 50

– 50

ns

tOEH

Hold time, OE command

15

18

20

ns

tOED

Hold time, OE to data delay

15

18

20

ns

NOTES:

8. All cycle times assume tT = 5 ns.

9. To ensure tPC min, tASC should be ≥ tCP .

10. In a read-write cycle, tRWD and tRWL must be observed.

11. In a read-write cycle, tCWD and tCWL must be observed.

12. Referenced to the later of CAS or W in write operations

13. The minimum value is measured when tRCD is set to tRCD min as a reference.

14. Either tRRH or tRCH must be satisfied for a read cycle.