mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 104

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Memories and Memory Interfaces
Module signals
Transfers
EzPort
Figure 3-19. EzPort configuration
Table 3-26. Reference links to related information
Topic
Related module
Reference
Full description
EzPort
EzPort
System memory map
System memory map
Clocking
Clock distribution
Transfers
Crossbar switch
Crossbar switch
Signal multiplexing
Port mux control
Signal multiplexing
3.6.5.1 EzPort and BDM
EzPort mode and active background debug mode (BDM) cannot be used at the same
time. Attempts to use both simultaneously can lead to unexpected behavior.
BDM has priority over EzPort mode. For more information, refer to the
detailed Boot
description.
3.6.5.2 Flash Option Register (FOPT)
The FOPT[EZPORT_DIS] bit can be used to prevent entry into EzPort mode during
reset. If the FOPT[EZPORT_DIS] bit is cleared, then the state of the chip select signal
(EZP_CS) is ignored and the MCU always boots in normal mode.
This option is useful for systems that use the EZP_CS/IRQ signal configured for its IRQ
function. Disabling EzPort mode prevents possible unwanted entry into EzPort mode if
the external circuit that drives the NMI signal asserts it during reset.
The FOPT register is loaded from the flash option byte. If the flash option byte is
modified, the new value takes effect for any subsequent resets, until the value is changed
again. For more information about the FOPT register, refer to
FOPT boot
options.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Preliminary
104
Freescale Semiconductor, Inc.