Datasheet

4337K–USB–04/08

AT89C5130A/31A-M

Reset Value = 0X0X 1100b

Not bit addressable

5 M0

Pulse length

Cleared to stretch MOVX control: the RD and the WR pulse length is 6 clock

periods (default).

Set to stretch MOVX control: the RD and the WR pulse length is 30 clock

periods.

4 -

Reserved

The value read from this bit is indeterminate. Do not set this bit

3 XRS1 ERAM Size

XRS1XRS0 ERAM size

0 0 256 bytes

0 1 512 bytes

1 0 768 bytes

1 1 1024 bytes (default)

2 XRS0

1 EXTRAM

EXTRAM bit

Cleared to access internal ERAM using MOVX at Ri at DPTR.

Set to access external memory.

0 AO

ALE Output bit

Cleared, ALE is emitted at a constant rate of 1/6 the oscillator frequency (or

1/3 if X2 mode is used) (default).

Set, ALE is active only when a MOVX or MOVC instruction is used.

Bit

Number

Bit

Mnemonic Description