MPC755 datasheet(18/56 Pages) NXP

18 / 56 page

MPC755 RISC Microprocessor Hardware Specifications, Rev. 8

Freescale Semiconductor

Electrical and Thermal Characteristics

Table 11. L2CLK Output AC Timing Specification

At recommended operating conditions (see Table 3)

Parameter

Symbol

All Speed Grades

Unit

Notes

Min

Max

L2CLK frequency

fL2CLK

450

MHz

1, 4

L2CLK cycle time

tL2CLK

2.5

12.5

L2CLK duty cycle

tCHCL/tL2CLK

2, 7

Internal DLL-relock time

640

—

L2CLK

3, 7

DLL capture window

5, 7

L2CLK_OUT output-to-output skew

tL2CSKW

—50

6, 7

L2CLK_OUT output jitter

—

±150

6, 7

Notes:

1. L2CLK outputs are L2CLK_OUTA, L2CLK_OUTB, L2CLK_OUT, and L2SYNC_OUT pins. The L2CLK frequency-to-core

frequency settings must be chosen such that the resulting L2CLK frequency and core frequency do not exceed their

respective maximum or minimum operating frequencies. The maximum L2LCK frequency will be system dependent.

L2CLK_OUTA and L2CLK_OUTB must have equal loading.

2. The nominal duty cycle of the L2CLK is 50% measured at midpoint voltage.

3. The DLL-relock time is specified in terms of L2CLK periods. The number in the table must be multiplied by the period of

L2CLK to compute the actual time duration in ns. Relock timing is guaranteed by design and characterization.

4. The L2CR[L2SL] bit should be set for L2CLK frequencies less than 110 MHz. This adds more delay to each tap of the DLL.

5. Allowable skew between L2SYNC_OUT and L2SYNC_IN.

6. This output jitter number represents the maximum delay of one tap forward or one tap back from the current DLL tap as the

phase comparator seeks to minimize the phase difference between L2SYNC_IN and the internal L2CLK. This number must

be comprehended in the L2 timing analysis. The input jitter on SYSCLK affects L2CLK_OUT and the L2 address/data/control

signals equally and, therefore, is already comprehended in the AC timing and does not have to be considered in the L2 timing

analysis.

7. Guaranteed by design.

MPC755 Datasheet(PDF) 18 Page - NXP Semiconductors

MPC755 Datasheet(HTML) 18 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

Datasheet Download

Link URL