NEC uPD78056Y User Manual

548

CHAPTER 26

PD78P054, 78P058

Notes 1. The internal ROM and internal high-speed RAM capacities are set as follows by RESET input:

Internal PROM: 32K bytes (

PD78P054), 60K bytes (

PD78P058)

Internal high-speed RAM: 1024 bytes

2. The internal expansion RAM is set to 1024 bytes by RESET input.

Caution

The noise immunity and noise radiation differ between PROM versions and mask ROM versions.

When considering replacement of PROM versions with mask ROM versions in the stage between

test production and mass production, evaluate thoroughly with CS products (not ES products)

of the mask ROM versions.

Remarks 1. The

PD78P054 is a PROM model corresponding to the

PD78052, 78053, and 78054.

The

PD78P058 is a PROM model corresponding to the

PD78055, 78056, and 78058.

2. Only the

PD78058 and 78P058 are provided with an internal expansion RAM size switching

Table 26-2. Differences between

PD78P054 and 78P058

Item

PD78P054

PD78P058

Internal PROM

32 Kbytes

60 Kbytes

Internal expansion RAM

Not provided

1024 bytes

Internal expansion RAM

Not provided

Provided

size switching register