S1K50000 Epson Electronics America, Inc., S1K50000 Datasheet - Page 19

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

Chapter 2: Precautions on Circuit Design
2.7 Bus Hold Circuits
14
Available with the S1K50000 series are input/output buffers with a bus hold function to hold the
input/output-pin data in order to prevent the output pins or bidirectional pins from entering a
high-impedance state.
However, because the retention capability of the bus hold circuit is repressed so as not to
adversely affect normal bus operation, do not use the retained output as valid data. If any data
is fed from an external device, the state of the data may change easily.
For details on the bus hold circuit’s output retention current, see Tables 1-5 through 1-7.
Used for testing
Output signal
Enable
(a) Output buffer
XTB1HT
A
E
TA
TE
TS
Figure 2-4 Typical Bus Hold Circuit Symbol
Output
EPSON
Used for testing
Output signal
Enable
Input signal
(b) Bidirectional buffer
XBC1HT
A
E
TA
TE
TS
STANDARD CELL S1K50000 SERIES
DESIGN GUIDE
Bidirectional