 English |
|
|
|
|
|
|
|
| PXS20RM Datasheet, PDF (1094/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller | |||
| |||
| ◁ |
Mode Entry Module (MC_ME)
32.4.3.1 Target Mode Request
The target mode is requested by accessing the ME_MCTL register with the required keys. This mode
transition request by software must be a valid request satisfying a set of pre-defined rules to initiate the
process. If the request fails to satisfy these rules, it is ignored, and the TARGET_MODE bit field is not
updated. An optional interrupt can be generated for invalid mode requests. Refer to Section 32.4.5, Mode
Transition Interrupts for details.
In the case of mode transitions occurring because of hardware events such as a reset, a SAFE mode request,
or interrupt requests and wakeup events to exit from low-power modes, the TARGET_MODE bit field of
the ME_MCTL register is automatically updated with the appropriate target mode. The mode change
process start is indicated by the setting of the mode transition status bit S_MTRANS of the register.
A RESET mode requested via the ME_MCTL register is passed to the MC_RGM, which generates a
global system reset and initiates the reset sequence. The RESET mode request has the highest priority, and
the MC_ME is kept in the RESET mode during the entire reset sequence.
The SAFE mode request has the next highest priority after reset. It can be generated either by software via
the ME_MCTL register from all software running modes including DRUN, RUN0â¦3, and TEST or by
the MC_RGM after the detection of system hardware failures, which may occur in any mode.
32.4.3.2 Target Mode Configuration Loading
On completion of the Target Mode Request step, the target mode configuration from the
ME_<target mode>_MC register is loaded to start the resources (voltage sources, clock sources, flash,
pads, etc.) control process.
An overview of resource control possibilities for each mode is shown in . A âïâ indicates that a given
resource is configurable for a given mode.
Table 32-16. MC_ME Resource Control Overview
Resourc
e
IRCOSC
XOSC
PLL0
PLL1
FLASH
RESET
on
off
off
off
normal
TEST
ï
on
ï
off
ï
off
ï
off
ï
normal
SAFE
on
off
off
off
normal
Mode
DRUN
on
ï
off
ï
off
ï
off
ï
normal
RUN0â¦3 HALT0
ï
on
on
ï
ï
off
off
ï
ï
off
off
ï
ï
off
off
ï
ï
normal low-power
STOP0
ï
on
ï
off
off
ï
off
ï
power-
down
32-38
PXS20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
|
▷ |
German
Russian
Spanish
Italian
Polish
Chinese
Japanese
Korean
French
Portuguese