MPC8378E PowerQUICC II Pro Processor Hardware Specifications, Rev. 8
66
Freescale Semiconductor
15.2
AC Requirements for PCI Express SerDes Clocks
This table lists the PCI Express SerDes clock AC requirements.
15.3
Clocking Dependencies
The ports on the two ends of a link must transmit data at a rate that is within 600 parts per million (ppm)
of each other at all times. This is specified to allow bit rate clock sources with a ±300 ppm tolerance.
15.4
Physical Layer Specifications
Following is a summary of the specifications for the physical layer of PCI Express on this device. For
further details as well as the specifications of the transport and data link layer, use the PCI Express Base
Specification, Rev. 1.0a.
NOTE
The voltage levels of the transmitter and the receiver depend on the SerDes
control registers which should be programmed at the recommended values
for PCI Express protocol (that is, L1_nVDD = 1.0 V).
Table 56. SD_REF_CLK and SD_REF_CLK AC Requirements
Parameter
Symbol
Min
Typical
Max
Unit
Note
REFCLK cycle time
tREF
—10
—
ns
—
REFCLK cycle-to-cycle jitter. Difference in the period of any
two adjacent REFCLK cycles.
tREFCJ
—
100
ps
—
REFCLK phase jitter peak-to-peak. Deviation in edge
location with respect to mean edge location.
tREFPJ
–50
—
+50
ps
—
SD_REF_CLK/_B cycle to cycle clock jitter (period jitter)
tCKCJ
—
100
ps
—
SD_REF_CLK/_B phase jitter peak-to-peak. Deviation in
edge location with respect to mean edge location.
tCKPJ
–50
—
+50
ps
Notes:
1. All options provide serial interface bit rate of 1.5 and 3.0 Gbps.
2. In a frequency band from 150 kHz to 15 MHz, at BER of 10-12.
3. Total peak-to-peak Deterministic Jitter “JD” should be less than or equal to 50 ps.