STK12C68-M

4-57

Note e:

These parameters guaranteed but not tested.

Note n:

HSB is an I/O that has a weak internal pullup; it is basically an open drain output. It is meant to allow up to 32 STK12C68-Ms to be ganged together for

simultaneous storing. Do not use HSB to pullup any external circuitry other than other STK12C68-M HSB pins.

Note o:

A RECALL cycle is initiated automatically at power up when V

22

RECALL Cycle Duration

20

µs

Note o

23

STORE Cycle Duration

10

ms

24

HSB Low to Inhibit On

1

µs

25

t

RECOVER

t

HHQX

HSB High to Inhibit Off

300

ns

Note e

26

t

ASSERT

t

HLHX

External

STORE Pulse Width

250

ns

Note e

Low Voltage Trigger Level

4.0

4.5

V

HSB Output Low Current

3

mA

HSB Output High Current

5

60

µA

NONVOLATILE MEMORY OPERATION

MODE SELECTION

H

X

H

X

Not Selected

Output High Z

Standby

L

H

H

X

Read SRAM

Output Data

Active

l

L

L

H

X

Write SRAM

Input Data

Active

L

H

H

0000

Read SRAM

Output Data

Active

k,l

1555

Read SRAM

Output Data

k,l

0AAA

Read SRAM

Output Data

k,l

1FFF

Read SRAM

Output Data

k,l

10F0

Read SRAM

Output Data

k,l

0F0F

Nonvolatile

STORE

Output High Z

k

L

H

H

0000

Read SRAM

Output Data

Active

k,l

1555

Read SRAM

Output Data

k,l

0AAA

Read SRAM

Output Data

k,l

1FFF

Read SRAM

Output Data

k,l

10F0

Read SRAM

Output Data

k,l

0F0E

Nonvolatile

RECALL

Output High Z

k

XX

L

X

STORE/Inhibit

Output High Z

m

E

W

HSB

MODE

I/O

POWER

NOTES

Note k: The six consecutive addresses must be in order listed - (0000, 1555, 0AAA, 1FFF, 10F0, 0F0F) for a

STORE cycle or (0000, 1555, 0AAA, 1FFF, 10F0,

0F0E) for a

RECALL cycle. W must be high during all six consecutive cycles. See STORE cycle and RECALL cycle tables and diagrams for further details.

Note l:

I/O state assumes that G

≤ V

Note m: HSB initiated

STORE operation actually occurs only if a WRITE has been done since last STORE operation. After the STORE (if any) completes, the

part will go into standby mode inhibiting all operation until HSB rises.

HARDWARE

STORE /RECALL

SYMBOLS

NO.

PARAMETER

MIN

MAX

UNITS

NOTES

2

HSB

W

RECALL

STORE

SRAM

Inhibit

Software STORE

HSB Initiated STORE

Power Down STORE

Brown Out RECALL

Power Up RECALL

24

26

22

24

25

23

23

23

HARDWARE

STORE /RECALL