MAC7200 datasheet(515/976 Pages) FREESCALE

515 / 976 page

Functional Description

MAC7200 Microcontroller Family Reference Manual, Rev. 2

Freescale Semiconductor

437

Figure 23-18. RESET Timing

The debug block reset is asserted together with the internal reset, but will not be extended by the external

RESET pin. In addition, the debug block reset will be asserted only if the reset sequence was initiated by

a power-on or low-voltage indication.

The Flash_POR signal is asserted on POR or LVR conditions. It will be synchronously released after

128+n clock cycles.

The reset sequence will be extended by m cycles till the Flash block acknowledges that it has completed

its reset. The number m will depend on the external crystal as well as on the characteristics of the Flash. It

will vary for each device.

This enables the user to activate the debugger in two ways: either by holding the reset input asserted while

the debugger is being activated or by setting up the debugger after a power-on reset, then applying an

additional reset that will not affect the debug logic (i.e. not a power-on reset).

Note that the Power-On reset sequence is not complete until least 8 cycles after the CRG releases the

RESET line. If another external reset occurs before the 8 cycles have expired, that new reset will also be

treated as a Power-On-Reset, so DEBUG_RESET will be asserted again.

with n being min 3 / max 6

cycles depending on internal

synchronization delay

RESET /

SYSCLK

SYS_RST

CRG drives RESET

RESET

pin released

only on power-on

) (

)

(

) (

)

(

) (

)

(

) (

)

(

) (

possibly

SYSCLK

not running

128 + n cycles

128 cycles 64 cycles

possibly

RESET driven

low externally

pin low

min 8 cycles

to complete

Power-On

reset sequence

m cycles

) (

)

(

) (

wait until

Flash reset is

complete

DEBUG_RST

FLASH_POR

EARLY_RST

) (

MAC7200 Datasheet(PDF) 515 Page - Freescale Semiconductor, Inc

MAC7200 Datasheet(HTML) 515 Page - Freescale Semiconductor, Inc

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 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL