Datasheet

MPC8308 PowerQUICC II Pro Processor Hardware Specification, Rev. 3
24 Freescale Semiconductor
USB
9.1.2 USB AC Electrical Specifications
This table lists the general timing parameters of the USB-ULPI interface.
The following two figures provide the AC test load and signals for the USB, respectively.
Figure 13. USB AC Test Load
Figure 14. USB Signals
Table 31. USB General Timing Parameters
Parameter Symbol
1
Min Max Unit Notes
USB clock cycle time t
USCK
15 — ns 1, 2
Input setup to USB clock—all inputs t
USIVKH
4 — ns 1, 4
Input hold to USB clock—all inputs t
USIXKH
1 — ns 1, 4
USB clock to output valid—all outputs t
USKHOV
—9ns1
Output hold from USB clock—all outputs t
USKHOX
1—ns1
Notes:
1. The symbols used for timing specifications follow the pattern of t
(First two letters of functional block)(signal)(state)(reference)(state)
for
inputs and t
(First two letters of functional block)(reference)(state)(signal)(state)
for outputs. For example, t
USIXKH
symbolizes usb timing
(US) for the input (I) to go invalid (X) with respect to the time the usb clock reference (K) goes high (H). Also, t
USKHOX
symbolizes usb timing (US) for the usb clock reference (K) to go high (H), with respect to the output (O) going invalid (X) or
output hold time.
2. All timings are in reference to USB clock.
3. All signals are measured from NVDD/2 of the rising edge of USB clock to 0.4  NVDD of the signal in question for 3.3-V
signaling levels.
4. Input timings are measured at the pin.
5. For purposes of active/float timing measurements, the Hi-Z or off-state is defined to be when the total current delivered
through the component pin is less than or equal to the leakage current specification.
Output
Z
0
= 50 
NVDD/2
R
L
= 50 
Output Signals
t
USKHOV
USBDR_CLK
Input Signals
t
USIXKH
t
USIVKH
t
USKHOX