UPD4991ACX Renesas Electronics America, UPD4991ACX Datasheet - Page 17

• Manufacturer Part Number: UPD4991ACX
• Manufacturer: Renesas Electronics America

Specifications of UPD4991ACX

• Lead Free Status / RoHS Status: Supplier Unconfirmed

2.1 Write Timing
CS
to be written, even when OE is always “L”.
STOP the CLK. A correct value may not be written to the time counter if data is written to the time counter while it
is operating. The other registers, however, are not affected.
Address A
WE takes precedence over OE (read enable). Therefore, data can be written by asserting WE only when data is
Figures 2-1 and 2-2 show the write timing. To change the setting of the time counter, it is necessary to RESET/
1
= “L” and CS
0
through A
ADDRESS
2
= “H” (chip select status).
D
WE
OE
CS
OUT
D
IN
3
and data D
0
t
t
OHZ
AS
through D
Figure 2-1. Write Cycle Timing 1
CHAPTER 2 OPERATIONS
3
are written to the IC when WE (write enable) is made high while
t
AW
t
CW
t
WC
t
WP
t
DW
t
WR
t
DH
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