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W921E840A Datasheet, PDF (46/58 Pages) Winbond – 4-BIT MICROCONTROLLER
W921E840A/W921C840
W921C840 Mask ROM Type
(VDD−VSS = 3.0V, FOSC = 4.0 MHz, TA = 25° C, all outputs unloaded)
PARAMETER
SYMBO
L
CONDITIONS
FOSC1
FOSC2
Operating Frequency
FOSC3 OSCI, OSCO
FOSC4
FOSC5
Operating Sub-frequency
FSUB
XT, XT
Instruction Cycle Time
TI
One Machine
Cycle
Serial Port Data Ready Time
TDR
−
Serial Port Data Hold Time
TDH
−
RESET Active Width
TRAW
−
ROW 1 Frequency (697Hz)
FROW1
FOSC = 4 MHz,
2 MHz, 800 KHz,
400 KHz
FOSC = 3.58 MHz
ROW 2 Frequency (770 Hz) FROW2 Same as ROW1
ROW 3 Frequency (852 Hz) FROW3 Same as ROW1
ROW 4 Frequency (941 Hz) FROW4 Same as ROW1
COL 1 Frequency (1209 Hz) FCOL1 Same as ROW1
COL 2 Frequency (1336 Hz) FCOL2 Same as ROW1
COL 3 Frequency (1477 Hz) FCOL3 Same as ROW1
COL 4 Frequency (1633 Hz) FCOL4 Same as ROW1
Oscillator Start Time
TOST
OSCO
MIN. TYP. MAX. UNIT
−
400
− KHz
−
800
− KHz
−
2
− MHz
−
3.58
− MHz
−
4
− MHz
− 32.768 − KHz
−
4/FOSC
−
S
200
−
−
nS
200
−
−
nS
2
−
−
TI
-0.5
−
+0.5
%
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
-0.5
−
+0.5 %
-0.92
− +0.92
−
17
2 /FOSC
−
mS
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