Texas Instruments 990 Operation Manual page 172

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The first example defines the ROM/PROM characteristics as follows:
ROM/PROM word width == 4 bits
High logic level output conditions (program Is)
Pulse width
=
3
Number of retries
=
2
Duty cycle
=
10
16
=
16 percent
Program 1 bit at a time
The second example defines the ROM/PROM characteristics as follows:
ROM/PROM word width
=
8 bits
Low logic level output conditions (program Os)
Pulse width
=
4
Number of retries
=
0 (default)
Duty cycle
=
25 percent (default)
Program 1 bit at a time (default)
7.5.3.9 Define String Width (SW). The Define String Width command informs the control soft-
ware of the width of the bit strings to be transferred between PROM/ROM and memory,
displayed, or compared to other bit strings.
Syntax definition:
PP
{t,' ... }
SW {b' ... } <width>
Parameter:
<width> The number of bits per bit string. A number in
the range 1 to 8. Required parameter.
Description: This subcommand sets the memory and PROM/ROM bit string width.
Error messages:
PPO 1 Required parameter missing.
PP02 String width outside the permissible range.
Example:
.PP,SW,1
This command defines the width of the string to be 1.
7-22
Digital Systems Division .