DSP56156FV40 MOTOROLA [Motorola, Inc], DSP56156FV40 Datasheet - Page 20

• Manufacturer Part Number: DSP56156FV40
• Description: 16-bit Digital Signal Processor
• Manufacturer: MOTOROLA [Motorola, Inc]

20
AC Electrical Characteristics and Timing
Clock Operation Timing
Num
1
2
3
4
5
6
7
8
AC Electrical Characteristics
(GND = 0 V dc)
The timing waveforms in the AC Electrical Characteristics are tested with a V
0.5 V and a V
MODC. These five pins are tested using the input levels set forth in the DC Electrical Charac-
teristics. AC timing specifications which are referenced to a device input signal are measured
in production with respect to the 50% point of the respective input signal’s transition. The
DSP56156 output levels are measured with the production test machine V
ence levels set at 0.8 V and 2.0 V respectively.
Clock Operation Timing
The system clock to the DSP56156 must be externally supplied to EXTAL as illustrated in
Figure 6.
NOTES: 1. Rise and fall time may be relaxed to 12 ns maximum if the EXTAL input frequency is less than or equal
Frequency of Operation (EXTAL)
Instruction Cycle Time = 2T
Wait State Time = T
EXTAL Cycle Period
EXTAL Rise Time (See Note 1)
EXTAL Fall Time (See Note 1)
EXTAL Width High
48-52% duty cycle
(See Notes 2, 3, 4)
EXTAL Width Low
48%-52% duty cycle
(See Notes 2, 3, 4)
2. The duty cycle may be relaxed to 43-57% if the EXTAL input frequency is less than or equal to 20 MHz.
3. T = I
4. Duty cycles and EXTAL widths are measured at the EXTAL input signal midpoint when AC coupled and
to 20 MHz. If the EXTAL input frequency is between 20 MHz and 40 MHz, rise and fall time should
meet the specified values in the 40 MHz column (4 ns maximum).
If the EXTAL input frequency is between 20 MHz and 40 MHz, the duty cycle should be such that T
and T
cycle of the external clock input.
at V
Characteristics
CC
IH
CYC
L
/2 when not AC coupled.
meet the specified values in the 40 MHz column (12 ns minimum).
minimum of 2.4 V for all pins, except EXTAL, RESET, MODA, MODB and
/ 4 is used in the electrical characteristics. The exact length of each T is affected by the duty
C
= 2T
Freescale Semiconductor, Inc.
C
Table 11 Clock Operation Timing
For More Information On This Product,
DSP56156 Data Sheet
Sym
I
CYC
T
T
—
T
Go to: www.freescale.com
f
C
H
L
Min
50
25
25
12
12
—
—
0
40 MHz
Max
40
×
×
×
4
4
×
×
Min
9.6
9.6
40
20
20
—
—
0
50 MHz
Max
50
×
×
×
×
×
3
3
16.6
16.6
Min
33
—
—
OL
0
8
8
60 MHz
and V
IL
maximum of
Max
60
×
×
×
×
×
3
3
MOTOROLA
OH
refer-
MHz
Unit
ns
ns
ns
ns
ns
ns
ns
H