Motorola MCF5281 사용자 설명서
MOTOROLA
Chapter 6. ColdFire Flash Module (CFM)
6-5
Memory Map
The CFM module has hardware interlocks to protect data from accidental corruption. The
CFM memory array is logically divided into 16-Kbyte sectors for the purpose of data
protection and access control. A flexible scheme allows the protection of any combination
of logical sectors (see Section 6.3.4.4, “CFM Protection Register (CFMPROT)”). A similar
mechanism is available to control supervisor/user and program/data space access to these
sectors.
CFM memory array is logically divided into 16-Kbyte sectors for the purpose of data
protection and access control. A flexible scheme allows the protection of any combination
of logical sectors (see Section 6.3.4.4, “CFM Protection Register (CFMPROT)”). A similar
mechanism is available to control supervisor/user and program/data space access to these
sectors.
6.3.1
CFM Configuration Field
The CFM configuration field comprises 24 bytes of reserved array memory space that
determines the module protection and access restrictions out of reset. Data to secure the
Flash from unauthorized access is also stored in the CFM configuration field. Table 6-1
describes each byte used in this field.
determines the module protection and access restrictions out of reset. Data to secure the
Flash from unauthorized access is also stored in the CFM configuration field. Table 6-1
describes each byte used in this field.
6.3.2
Flash Base Address Register (FLASHBAR)
The configuration information in the Flash base address register (FLASHBAR) controls the
operation of the Flash module.
operation of the Flash module.
• The FLASHBAR holds the base address of the Flash. The MOVEC instruction
provides write-only access to this register.
• The FLASHBAR can be read or written from the debug module in a similar manner.
• All undefined bits in the register are reserved. These bits are ignored during writes
• All undefined bits in the register are reserved. These bits are ignored during writes
to the FLASHBAR, and return zeroes when read from the debug module.
• The back door enable bit, FLASHBAR[BDE], is cleared at reset, disabling back
door access to the Flash.
Table 6-1. CFM Configuration Field
Address Offset (from array base
address)
Size
in Bytes
Description
0x0000_0400–0x0000_0407
8
Back door comparison key
0x0000_0408–0x0000_040B
4
Flash program/erase sector protection
Blocks 0H/0L (see Section 6.3.4.4, “CFM Protection Register (CFMPROT)”)
Blocks 0H/0L (see Section 6.3.4.4, “CFM Protection Register (CFMPROT)”)
0x0000_040C–0x0000_040F
4
Flash supervisor/user space restrictions
Blocks 0H/0L (see Section 6.3.4.5, “CFM Supervisor Access Register
(CFMSACC)”)
Blocks 0H/0L (see Section 6.3.4.5, “CFM Supervisor Access Register
(CFMSACC)”)
0x0000_0410–0x0000_0413
4
Flash program/data space restrictions
Blocks 0H/0L (see Section 6.3.4.6, “CFM Data Access Register
(CFMDACC)”)
Blocks 0H/0L (see Section 6.3.4.6, “CFM Data Access Register
(CFMDACC)”)
0x0000_0414–0x0000_0417
4
Flash security longword (see Section 6.3.4.3, “CFM Security Register
(CFMSEC)”)
(CFMSEC)”)