HD64F3437TF16 Datasheet, PDF (8/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

Notes on S-Mask Model
(Single-Power-Supply Specification)
There are two versions of the H8/3437F with on-chip flash memory: a dual-power-supply version
and a single-power-supply (S-mask) version. Points to be noted when using the H8/3437F single-
power-supply S-mask model are given below.
1. Notes on Voltage Application
12 V must not be applied to the S-mask model (single-power-supply specification), as this may
permanently damage the device.
The flash memory programming power supply for the S-mask model (single-power-supply
specification) is V_CC. The programming power supply for the dual-power-supply model is the FV_PP
pin (12 V), but the single-power-supply model (S-mask model) does not have an FV_PP pin.
Also, in boot mode, 12 V has to be applied to the MD₁ pin in the dual-power-supply model, but 12
V application is not necessary in the single-power-supply model (S-mask model).
The maximum rating of the MD₁ pin is V_CC +0.3 V. Applying a voltage in excess of the
maximum rating will permanently damage the device.
Do not select the HN28F101 programmer setting for the S-mask model (single-power-supply
specification). If this setting is made by mistake, 12 V will be applied to the STBY pin, possibly
causing permanent damage to the device.
When using a PROM programmer to program the on-chip flash memory in the S-mask model
(single-power-supply specification), use a PROM programmer that supports Hitachi
microcomputer devices with 64-kbyte on-chip flash memory. Also, only use the specified socket
adapter. Using the wrong PROM programmer or socket adapter may damage the device.
The following PROM programmers support the S-mask model (single-power-supply
specification).
DATA I/O: UNISITE, 2900, 3900, etc.
Minato: 1892, 1891, 1890, etc.