mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 165

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

6.3 Boot
The boot description includes information about boot sources and boot options available
in the MCU.
6.3.1 Boot sources
The chip only supports booting from internal flash. Any secondary boot must go through
an initialization sequence in flash.
6.3.2 Boot options
The device's functional mode is controlled by the two mode select (MS) pins, which have
the following relative priority:
The mode select functionality on these pins does not depend on the pin muxing setting of
the pins. Upon power on reset, these pins are analyzed and the different modes are
entered depending on the level provided on these pins.
By default, the device comes out of reset in functional mode. In functional mode, the
device will be in single chip (default) mode. While in single chip mode only, the device
can be in run mode or various low power modes described in
Freescale Semiconductor, Inc.
1. The BKGD/MS pin is used to select between active background debug mode (BDM)
2. The EZP_MS pin selects between EzPort serial flash programming mode and single
and single chip modes.
chip mode.
Field
MS
0
0
1
MS_B pin state
Reflects the state of the MS pin during the last Chip Reset
0
1
Pin negated (logic 1)
Pin asserted (logic 0)
Pin negated (logic 1)
Pin asserted (logic 0)
MCF51JF128 Reference Manual, Rev. 2, 03/2011
RCM_MR field descriptions (continued)
Preliminary
Description
Modes of
Chapter 6 Reset and Boot
Operation.
165