Information Technology Reference
In-Depth Information
_outp(0x3E0,07h); /* point to I/O Control register */
_outp(0x3E1,00h); /* load 00h into register */
/* enable window 0 */
_outp(0x3E0,06h); /* point to memory enable window */
_outp(0x3E1,04h); /* load 0100 0000b to enable I/O window 0 */
8.4
Exercises
8.4.1
How many data bits does the PCMCIA bus have:
(a)
8
(b)
16
(c)
24
(d)
32
8.4.2
How are devices typically added to the system:
(a)
They are mapped into the I/O memory address
(b)
They directly into the physical address of the system
(c)
They use polled interrupts
(d)
They interface to a main controller
8.4.3
What is the base address of the registers that are used to program the PCMCIA
device:
(a)
1E0h
(b)
2E0h
(c)
3E0h
(d)
4E0h
8.4.4
Prove that the maximum address memory with PCMCIA is 64 MB.
8.4.5
Explain how I/O registers are used to program the PCMCIA device.
8.4.6
Show the lines of C code that would be required to mount a primary serial port
(3F8h-3FFh) and an ECP printer port (378h-37Ah).
8.4.7
Show the lines of C code that would be required to mount a primary (1F0h-1F7h)
and a secondary hard disk (170h-177h).
8.4.8
How would the programming for extra memory differ from an isolated I/O device.
8.5
Notes from the author
PCMCIA devices - To save paper, I've got seven lines to tell you about them. Well, in sum-
mary, they're really good, but tend to be relatively expensive. Their principle use is to add a
network adapter or a modem to a notebook computer. They are typically not used to add to
the memory of the notebook or to increase its hard disk space (an internal upgrade is much
better for these). Personally, I find them a little too thin, and I do not believe they can get all
the required electronics into them (but I remember when simple logic ICs, like AND and OR
gates, were as big as your thumb and they could heat it if you required).
