S1K50000 Epson Electronics America, Inc., S1K50000 Datasheet - Page 87

• Manufacturer Part Number: S1K50000
• Description: Design Guide S1k50000 Series
• Manufacturer: Epson Electronics America, Inc.

Chapter 6: Creating Test Patterns
82
<Corrective measures>
When test patterns are checked, all occurrences of “Z” in bidirectional pins are indicated by the
generation of an error (this does not include the “Z” that is used in the expression of tri-state
and N-channel open-drain output pins).
As a means of correcting input patterns, Seiko Epson uses a utility program that automatically
replaces the “Z” in said bidirectional pins with logic “1” if they have a pull-up resistor, or with
logic “0” if they have a pull-down resistor.
For bidirectional pins, if a pin containing the letter “X” is set for the input mode, the “X” is
propagated in simulation. In the simulation result, it is expressed as “?,” regardless of whether
the pin comes with a pull-up/down resistor. Customers are requested to correct the input
pattern for occurrences of “?” before Seiko Epson reexecutes simulation.
Input Pattern
“1”, “H”
“0”, “L”
“X”
Table 6-1 Handling of Bidirectional-Pin Signals in Simulation
Input/Output Mode
Input Mode
Input Mode
Input Mode
EPSON
Simulation
“X”
“1”
“0”
STANDARD CELL S1K50000 SERIES
Simulation Result
(Output Pattern)
“?”
“1”
“0”
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