MC9328MX21_10 Datasheet, PDF (17/100 Pages) Freescale Semiconductor, Inc – 266 MHz i.MX family of microprocessors

Specifications
All timing is measured at 30 pF loading with the exception of fast I/O signals as discussed below. Refer
to the reference manual’s System Control Chapter for details on drive strength settings.
Table 8 provides the maximum loading guidelines that can be tolerated on a memory I/O signal (also
known as Fast I/O) to achieve 133 MHz operation. These critical signals include the SDRAM Clock
(SDCLK), Data Bus signals (D[31:0]), lower order address signals such as A0-A10, MA10, MA11, and
other signals required to meet 133 MHz timing.
The values shown in Table 8 apply over the recommended operating temperature range. Care must be
taken to minimize parasitic capacitance of associated printed circuit board traces.
Table 8. Loading Guidelines for Fast IO Signals to Achieve 133 MHz Operation
Drive Strength Setting (DSCR2–DSCR12)
000: 3.5 mA
001: 4.5 mA
011: 5.5 mA
111: 6.5 mA
Maximum I/O Loading at 1.8 V
9 pF
12 pF
15 pF
19 pF
Maximum I/O Loading at 3.0 V
12 pF
16 pF
21 pF
26 pF
Table 9. 32k/26M Oscillator Signal Timing
Parameter
EXTAL32k input jitter (peak to peak) for both System PLL and MCUPLL
EXTAL32k input jitter (peak to peak) for MCUPLL only
EXTAL32k startup time
Minimum
–
–
800
RMS
5
5
–
Maximum Unit
20
ns
100
ns
–
ms
Table 10. CLKO Rise/Fall Time (at 30pF Loaded)
Best Case Typical Worst Case Units
Rise Time
0.80
1.00
1.40
ns
Fall Time
0.74
1.08
1.67
ns
3.5 DPLL Timing Specifications
Parameters of the DPLL are given in Table 11. In this table, T_ref is a reference clock period after the
predivider and T_dck is the output double clock period.
Table 11. DPLL Specifications
Parameter
Reference clock frequency range
Pre-divider output clock frequency
range
Double clock frequency range
Pre-divider factor (PD)
Total multiplication factor (MF)
Test Conditions
Vcc = 1.5V
Vcc = 1.5V
Vcc = 1.5V
–
Includes both integer and fractional parts
Minimum
16
16
Typical
–
–
Maximum
320
32
220
–
560
1
–
16
5
–
15
Unit
MHz
MHz
MHz
–
–
MC9328MX21 Technical Data, Rev. 3.4
Freescale Semiconductor
17