Advertisement
Setting up the CRI Port involves:
VI .1 . . , HARDWARE JUMPERS
INPUT JUMPER AREA
In the INPUT JUMPER AREA:
CRI BIT RATE JUMPER AREA
The bit rate for recording data is formed by
dividing down ,02.
select any data rate from 488 to 62,500 bits
per second.
presetting an 8 bit counter and counting it
up to 255, at which time it is reloaded.
output of this counter is further divided
by 16 to form the final recording speed.
formula for determining the preset value is:
(in base 10).
In the CRI Bit Rate Jumper Area, Row A pro
vides Ground (used when the preset is a zero).
Row B provides +V (used when the preset value
is a o n e ) , and Row C is the counter input.
Table. 11 gives the standard bit rates.
30
1. configuring the hardware jumpers;
2. making the external interface
connections; and
3. running test programs to check
out the operation of the port.
The status signal CRIS (D4) must be
jumpered to the desired input bit of
the Control Port (Row A ) .
CRIS
This signal goes high to indicate to
the processor when a bit or byte is
ready.
It may be jumpered to the
Interrupt Lines or to the Input bits
of the Control Port.
of the Control Output Port is used to
select a bit or byte ready (see Table 3).
This permits the User to
The division is accomplished by
P.V. = 256 - (125,000/BIT RATE)
MIO
User Guide
Note that bit 6
The
The
Advertisement
