TMS27C256 32768 BY 8-BIT UV ERASABLE

TMS27PC256 32768 BY 8-BIT

PROGRAMMABLE READ-ONLY MEMORIES

SMLS256H– SEPTEMBER 1984 – REVISED NOVEMBER 1997

9

POST OFFICE BOX 1443

PARAMETER MEASUREMENT INFORMATION

2.08 V

RL = 800 Ω

Output

Under Test

CL = 100 pF

(see Note A)

NOTE A: CL includes probe and fixture capacitance.

ac testing input / output wave forms

2.4 V

0.4 V

0.8 V

0.8 V

2 V

2 V

AC testing inputs are driven at 2.4 V for logic high and 0.4 V for logic low. Timing measurements are made at

2 V for logic high and 0.8 V for logic low for both inputs and outputs.

Figure 2. AC Testing Output Load Circuit

A0 – A14

E

Addresses Valid

ta(E)

G

DQ0 – DQ7

Hi-Z

ten(G)

tv(A)

tdis

Output Valid

VIH

VIL

VIH

VIL

VIH

VIL

VOH

VOL

Hi-Z

ta(A)

Figure 3. Read-Cycle Timing