Motorola MPC5200 Manual de usuario descargar pdf (Pagina 17)

Electrical and Thermal Characteristics

MPC5200 Data Sheet, Rev. 4

Freescale Semiconductor 17

For additional information, see the MPC5200 User Manual [1].

NOTE

Make sure that the PORRESET

does not carry any glitches. The MPC5200

has no filter to prevent them from getting into the chip.

NOTE

HRESET

and SRESET must have a monotonous rise time.

3.3.3.1 Reset Configuration Word

During reset (HRESET and PORRESET) the Reset Configuration Word is cached in the related Reset

Configuration Word Register with each rising edge of the SYS_XTAL signal. If both resets (HRESET

and

PORRESET

) are inactive (high), the contents of this register get locked after two further SYS_XTAL

cycles (see Figure 3).

Figure 3. Reset Configuration Word Locking

Table 15. Reset Rise / Fall Timing

Description Min Max Unit SpecID

PORRESET

fall time — 1 ms A3.4

PORRESET

rise time — 1 ms A3.5

HRESET

fall time — 1 ms A3.6

HRESET

rise time — 1 ms A3.7

SRESET

fall time — 1 ms A3.8

SRESET

rise time — 1 ms A3.9

sample

sample sample

sample

LOCK

RST_CFG_WRD

HRESET

PORRESET

SYS_XTAL

4096 clocks 2 clocks

1 2 ... 12 13 14 15 16 17 18 19 20 21 22 ... 79 80

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Motorola MPC5200 Manual de usuario Pagina 17