Specifications

Processor Description (V40)
COMMONLY ASKED QUESTIONS
1. Is the V40 pin-compatible with the 80188?
The V40 and 80188 are not pin-compatible. This means an
80188 cannot be plugged into the V40 socket. This is unlike the
V20 and V30, which are interchangeable with the 8088 and
8086, respectively.
2. What are the hardware differences between the V40 and the
80188?
One of the most notable differences is that the V40 is fabricated
with a CMOS process. CMOS technology provides an increase
in both temperature range and noise immunity, with a reduction
in power consumption. The CMOS V40 has a maximum power
dissipation of less than 1/2 W and a standby dissipation of less
than 1/10 W. The 80188 has a maximum power dissipation of
3 W; that is, too hot to touch.
Other differences are as follows: the V40 includes an asynchro-
nous serial port; the V40 interrupt controller and counter/timers
have the same architecture as the interrupt controller and
counter/timers used in the Personal Computer; and the data
transfer rate for the V40 DMA controller is twice as fast.
3. Is the V40 software compatible with the 8088 and 80188
microprocessors?
Yes. The V40 instruction set is 100% object code compatible
with the 80188 instruction set. This means that a program
written for the 8088 or 80188 will execute on the V40.
Application software using the peripherals internal to the 80188
requires some modification.
4. What are the V40 instructions not in the 8088 or 80188 and
how are they used?
The V40 instruction set is a superset of the 8088 and 80188.
This means the V40 includes all of the instructions found in
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