
56F8367 Technical Data, Rev. 7.0
148
Freescale Semiconductor
Preliminary
10.7 Crystal Oscillator Timing
10.8 External Memory Interface Timing
The External Memory Interface is designed to access static memory and peripheral devices. Figure 10-4
shows sample timing and parameters that are detailed in Table 10-16.
The timing of each parameter consists of both a fixed delay portion and a clock related portion, as well as
user controlled wait states. The equation:
t = D + P * (M + W)
should be used to determine the actual time of each parameter. The terms in this equation are defined as:
When using the XTAL clock input directly as the chip clock without prescaling (ZSRC selects prescaler
clock and prescaler set to ÷ 1), the EMI quadrature clock is generated using both edges of the EXTAL clock
input. In this situation only, parameter values must be adjusted for the duty cycle at XTAL. DCAOE and
DCAEO are used to make this duty cycle adjustment where needed.
Table 10-15 Crystal Oscillator Parameters
Characteristic
Symbol
Min
Typ
Max
Unit
Crystal Start-up time
TCS
45
10
ms
Resonator Start-up time
TRS
0.1
0.18
1
ms
Crystal ESR
RESR
——
120
ohms
Crystal Peak-to-Peak Jitter
TD
70
—
250
ps
Crystal Min-Max Period Variation
TPV
0.12
—
1.5
ns
Resonator Peak-to-Peak Jitter
TRJ
——
300
ps
Resonator Min-Max Period Variation
TRP
——
300
ps
Bias Current, high-drive mode
IBIASH
—250
290
A
Bias Current, low-drive mode
IBIASL
—80
110
A
Quiescent Current, power-down mode
IPD
—0
1
A
t
= Parameter delay time
D
= Fixed portion of the delay, due to on-chip path delays
P
= Period of the system clock, which determines the execution rate of the part
(i.e., when the device is operating at 60MHz, P = 16.67 ns)
M
= Fixed portion of a clock period inherent in the design; this number is adjusted to account
for possible derating of clock duty cycle
W
= Sum of the applicable wait state controls. The “Wait State Controls” column of
Table 10-16 shows the applicable controls for each parameter and the EMI chapter of
the 56F8300 Peripheral User Manual details what each wait state field controls.