HD64F3437TF16 Datasheet, PDF (642/752 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.

A.2 Operation Code Map
Table A.2 is a map of the operation codes contained in the first byte of the instruction code (bits
15 to 8 of the first instruction word).
Some pairs of instructions have identical first bytes. These instructions are differentiated by the
first bit of the second byte (bit 7 of the first instruction word).
Instruction when first bit of byte 2 (bit 7 of first instruction word) is 0.
Instruction when first bit of byte 2 (bit 7 of first instruction word) is 1.
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