UPD78P4916 Datasheet, PDF (12/56 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD78P4916
* ^{1. DIFFERENCES BETWEEN µPD78P4916 AND µPD784915, µPD784916A}
Other than the memory types, their capacities, and memory-related points, the functions of the three devices are
identical: the µPD78P4916 incorporates a one-time PROM that is rewritable by users, while the µPD784915 and
784916A contain mask ROMs.
Table 1-1 shows the differences among these devices. Be sure to keep in mind these differences especially when
debugging and pre-producing the application system with the PROM version and then mass-producing it with the
mask-ROM version.
For the details about the CPU functions and on-chip hardware, refer to the µPD784915 Subseries User’s
Manual—Hardware (U10444E).
Table 1-1. Differences among µPD784915 Subseries Devices
Parameters
µPD78P4916
µPD784915
µPD784916A
Internal ROM
One-time PROM
Mask ROM
Mask ROM
62 Kbytes^Note
48 Kbytes
62 Kbytes
Internal RAM
2048 bytes^Note
1280 bytes
1280 bytes
Internal memory size select register (IMS) Provided
Not provided
Not provided
Pinouts
Pins related to PROM writing and reading are provided on the µPD78P4916.
Other
There are differences in noise immunity, noise radiation, and some electrical
specifications, because of the differences in circuit complexity and mask
layout.
Note The internal PROM and RAM capacities of the µPD78P4916 can be changed through its internal memory
size select register (IMS).
Caution There are differences in noise immunity and noise radiation between the PROM and mask-ROM
versions. When pre-producing the application set with the PROM version and then mass-
producing it with the mask-ROM version, be sure to conduct sufficient evaluations for the set
using consumer samples (not engineering samples) of the mask-ROM version.
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