User`s manual

Device Specifications
C501
Semiconductor Group 10-4
Notes:
1)
Capacitive loading on ports 0 and 2 may cause spurious noise pulses to be superimposed on the V
OL
of ALE
and port 3. The noise is due to external bus capacitance discharging into the port 0 and port 2 pins when these
pins make 1-to-0 transitions during bus operation. In the worst case (capacitive loading > 100 pF), the noise
pulse on ALE line may exceed 0.8 V. In such cases it may be desirable to qualify ALE with a schmitt-trigger,
or use an address latch with a schmitt-trigger strobe input.
2)
Capacitive loading on ports 0 and 2 may cause the V
OH
on ALE and PSEN to momentarily fall bellow the
0.9
V
CC
specification when the address lines are stabilizing.
3)
I
PD
(Power Down Mode) is measured under following conditions:
EA
= Port0 = V
CC
; RESET = V
SS
; XTAL2 = N.C.; XTAL1 = V
SS
; all other pins are disconnected.
4)
I
CC
(active mode) is measured with:
XTAL1 driven with
t
CLCH
, t
CHCL
= 5 ns, V
IL
= V
SS
+ 0.5 V, V
IH
= V
CC
– 0.5 V; XTAL2 = N.C.;
EA
= Port0 = RESET= V
CC
; all other pins are disconnected. I
CC
would be slightly higher if a crystal oscillator is
used (appr. 1 mA).
5)
I
CC
(Idle mode) is measured with all output pins disconnected and with all peripherals disabled;
XTAL1 driven with
t
CLCH
, t
CHCL
= 5 ns, V
IL
= V
SS
+ 0.5 V, V
IH
= V
CC
– 0.5 V; XTAL2 = N.C.;
RESET = EA
= V
SS
; Port0 = V
CC
; all other pins are disconnected;
7)
I
CC max
at other frequencies is given by:
active mode:
I
CC
= 1.27 x f
OSC
+ 5.73
idle mode:
I
CC
= 0.28 x f
OSC
+ 1.45 (C501-L and C501-1R only)
where
f
OSC
is the oscillator frequency in MHz. I
CC
values are given in mA and measured at V
CC
= 5 V.