upd4704 Renesas Electronics Corporation., upd4704 Datasheet - Page 5

• Manufacturer Part Number: upd4704
• Description: Extension 8-bit Up/down Counter Cmos Integrated Circuits
• Manufacturer: Renesas Electronics Corporation.

(3) Carry & borrow outputs
Carry output (the pulse width is virtually the same as the UP or DOWN pulse L period). Similarly, if the counter
performs a down-count operation when the count value is 00
A Borrow pulse is also output if a down-count operation is performed while RESET is "H" (during a reset), and
therefore, when a PD4704 is added, a reset must be executed at the same time.
If the counter performs an up-count operation when the count value is 0FF
UP/DOWN
UP/DOWN
RESET
STB
STB
Pre-count value latched
Fig. 2 Relation Between STB Timing and Counter Value
t
SUDSTB1
Fig. 3 STB and RESET Timing
t
SUDSTB1
If STB changes from "H" to "L" and a reset is
executed in this period, the latch is also reset.
Either pre- or post-count value latched
t
SUDSTB2
H
, an active-low pulse is output to the Borrow output.
Post-count value latched
t
DUDCD
H
, an active-low pulse is output to the
PD4704
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