UPD784915B Datasheet, PDF (11/86 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784915B, 784916B
1. DIFFERENCES AMONG µPD784915 SUBSERIES PRODUCTS
The µPD784915 Subseries consists of the six products listed in Table 1-1. The µPD784915A is a low-cost process-
shrinked version of the µPD784915. The µPD784916A expands the internal ROM capacity of the µPD784915 to 62
Kbytes. The µPD784915B and 784916B feature improved electrical characteristics compared to the µPD784915A
and 784916A.
The µPD78P4916 features writable one-time PROM instead of the mask ROM of the µPD784915, 784915A,
784916A, 784915B, and 784916B. Except for this substitution of PROM for ROM and the fact that PROM capacity
differs from the ROM capacities offered in the other products, the µPD78P4916 has the same functions as those
products.
In switching from the PROM product, used for debugging and testing application systems, to the mask ROM
products for mass production, be careful to check the differences among these products.
For details on the CPU functions and the internal hardware, refer to µPD784915 Subseries User’s Manual —
Hardware (U10444E).
Table 1-1. Differences among µPD784915 Subseries Products
Item
Internal ROM
Internal RAM
Internal memory capacity
selection register (IMS)
Electrical characteristics
Pin connections
µPD784915,
784915A
Mask ROM
49152 bytes
1280 bytes
Not provided
µPD784916A
µPD784915B
µPD784916B
63488 bytes
49152 bytes
63488 bytes
µPD78P4916
63232 bytes ^Note
2048 bytes^Note
Provided
The electrical characteristics of the µPD784915A/784916A, the µPD784915B/784916B,
and the µPD78P4916 differ with respect to the items listed below.
• P40 to P47, P50 to P57: Low-level input voltage
• VDD supply current
• Data hold current
• CTL amplifier: Phase signal elimination ratio
• CFG amplifier: CFGAMPO low-level output current
For details, refer to the data sheet of each product.
• µPD784915A/784916A Data Sheet (U11022J)
• µPD784915B/784916B Data Sheet (This document)
• µPD78P4916
Data Sheet (U11045J)
In the µPD78P4916, pin function for PROM read/write has been added.
Note The internal PROM and internal RAM capacities can be changed using the internal memory selection register
(IMS).
Caution
The PROM version and mask ROM version differ in noise immunity and noise radiation, etc. When
considering replacing a PROM version with a mask ROM version when switching from preproduction
to volume production, perform sufficient evaluation using a CS version (not ES version) of the
mask ROM version.
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