Freescale Semiconductor MCF52211 ユーザーズマニュアル
EzPort
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor
19-7
19.4.1.8
Sector Erase
The Sector Erase command erases the contents of a 2-Kbyte space of flash memory. The 3-byte address
sent after the command byte can be any address within the space to erase.
sent after the command byte can be any address within the space to erase.
This command should not be used if the write error flag is set, a write is in progress, the write enable bit
is not set, or the configuration register has not been written. This command is not accepted if flash security
is enabled.
is not set, or the configuration register has not been written. This command is not accepted if flash security
is enabled.
The write error flag sets if there is an attempt to erase a protected area of the flash memory.
19.4.1.9
Bulk Erase
The Bulk Erase command erases the entire contents of flash memory, ignoring any protected sectors or
flash security. The write error flag sets if the Bulk Erase command does not successfully erase the entire
contents of flash memory. Flash security is disabled if the Bulk Erase command is followed by a Reset
Chip command.
flash security. The write error flag sets if the Bulk Erase command does not successfully erase the entire
contents of flash memory. Flash security is disabled if the Bulk Erase command is followed by a Reset
Chip command.
This command should not be used if the write error flag is set, a write is in progress, the write enable bit
is not set, or the configuration register has not been written.
is not set, or the configuration register has not been written.
19.4.1.10 Reset Chip
The Reset Chip command forces the chip into the reset state. If the EzPort chip select (EZPCS) pin is
asserted at the end of the reset period, EzPort is enabled; otherwise, it is disabled.
asserted at the end of the reset period, EzPort is enabled; otherwise, it is disabled.
This command allows the chip to boot up from flash memory after it has been programmed by an external
source.
source.
This command should not be used if a write is in progress.
19.5
Functional Description
The EzPort provides a simple interface to connect an external device to the flash memory on board a 32
bit microcontroller.
bit microcontroller.
The interface itself is compatible with the SPI interface (with the EzPort operating as a slave) running in
either of the two following modes with data transmitted most significant bit first:
either of the two following modes with data transmitted most significant bit first:
•
CPOL = 0, CPHA = 0
•
CPOL = 1, CPHA = 1
Commands are issued by the external device to erase, program, or read the contents of the flash memory.
The serial data out from the EzPort is tri-stated unless data is being driven, allowing the signal to be shared
among several different EzPort (or compatible) devices in parallel, provided they have different chip
selects.
The serial data out from the EzPort is tri-stated unless data is being driven, allowing the signal to be shared
among several different EzPort (or compatible) devices in parallel, provided they have different chip
selects.