PMC-Sierra, Inc.
PM6541 E1XC-EVBD
TELECOM STANDARD PRODUCT
PMC-930917
ISSUE 1
E1XC EVALUATION DAUGHTERBOARD
6 IMPLEMENTATION DESCRIPTION
The E1XC EVBD (PM6541) is the T1XC EVBD (PM4541) with different stuffing
options. The following are the differences between the two products:
1.) Two PM6341s are stuffed instead of two PM4341s.
2.) Oscillator U1 is not stuffed.
3.) Socket U2 is stuffed with a 49.152 MHz oscillator.
4.) Several resistor values are changed:
R4 = R9 = 523 Ω (1%)
R3 = R8 = 4.53 kΩ (1%)
R20 = R22 = 1 kΩ (5%)
5.) Stuff C1 and C4 with a 1 nF capacitor and a 47 Ω resistor in series.
The E1XC EVBD should be shipped with header shunts between the following pins:
J25 - pins 1 and 2
J19 - pins 3 and 4
J20 - pins 3 and 4
J21 - pins 5 and 6
J22 - pins 5 and 6
J23 - pins 5 and 6
J24 - pins 5 and 6
J22 - pins 5 and 6
J30 - pins 1 and 2
J31 - pins 1 and 2
J32 - pins 1 and 2
6.1
BusTransceivers
Bus Transceivers have been used on the daughterboard to minimize the loading
presented to the motherboard microprocessor. Two 74HCT244's buffer all eight
upper address bits, the microprocessor control signals, and the external clock and
framing pulse inputs. A single 74HCT245 provides the bi-directional buffering of the
15
PMC [ PMC-SIERRA, INC ]
