MPC875 datasheet(23/84 Pages) FREESCALE

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MPC875/MPC870 Hardware Specifications, Rev. 3.0

PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE

Freescale Semiconductor

Bus Signal Timing

B42

CLKOUT rising edge to TS valid (hold

time) (MIN = 0.00

× B1 + 2.00)

2.00

—

2.00

—

2.00

—

2.00

—

B43

AS negation to memory controller signals

negation (MAX = TBD)

—TBD

1 For part speeds above 50 MHz, use 9.80 ns for B11a.

2 The timing required for BR input is relevant when the MPC875/870 is selected to work with the internal bus arbiter.

The timing for BG input is relevant when the MPC875/870 is selected to work with the external bus arbiter.

3 For part speeds above 50 MHz, use 2 ns for B17.

4 The D(0:31) input timings B18 and B19 refer to the rising edge of the CLKOUT in which the TA input signal is asserted.

5 For part speeds above 50 MHz, use 2 ns for B19.

6 The D(0:31) input timings B20 and B21 refer to the falling edge of the CLKOUT. This timing is valid only for read

accesses controlled by chip-selects under control of the user-programmable machine (UPM) in the memory

controller, for data beats where DLT3 = 1 in the RAM words. (This is only the case where data is latched on the falling

edge of CLKOUT.)

7 The timing B30 refers to CS when ACS = 00 and to WE(0:3) when CSNT = 0.

8 The signal UPWAIT is considered asynchronous to the CLKOUT and synchronized internally. The timings specified in

B37 and B38 are specified to enable the freeze of the UPM output signals as described in Figure 19.

9 The AS signal is considered asynchronous to the CLKOUT. The timing B39 is specified in order to allow the behavior

specified in Figure 22.

Table 10. Bus Operation Timings (continued)

Num

Characteristic

33 MHz

40 MHz

66 MHz

80 MHz

Unit

Min

Max

Min

Max

Min

Max

Min

Max

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