PXD10RM Datasheet, PDF (625/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

The UMISR4 Register is not accessible whenever MCR.DONE or UT0.AID are low: reading returns
indeterminate data while writing has no effect.
Table 17-58. UMISR4 field descriptions
Field
Description
0:31 MS159-128: Multiple input Signature 159-128 (Read/Write)
These bits represent the MISR value obtained accumulating:
the 8 ECC bits for the even Double Word (on MS135-128);
the single ECC error detection for even Double Word (on MS138);
the double ECC error detection for even Double Word (on MS139);
the 8 ECC bits for the odd Double Word (on MS151-144);
the single ECC error detection for odd Double Word (on MS154);
the double ECC error detection for odd Double Word (on MS155).
The MS can be seeded to any value by writing the UMISR4 register.
17.3.7 Programming considerations
17.3.7.1 Modify Operation
All the Modify Operations of the Flash Module are managed through the Flash User Registers Interface.
All the sectors of the Flash Module belong to the same partition (Bank), therefore when a Modify operation
is active on some sectors no read access is possible on any other sector (Read-While-Modify is not
supported).
During a Flash Modify Operation any attempt to read any Flash location will output invalid data and bit
RWE of MCR will be automatically set. This means that the Flash Module is not fetchable when a Modify
Operation is active: The Modify Operation commands must be executed from another Memory (internal
Ram or external Memory).
If during a Modify Operation a reset occurs, the operation is suddenly terminated and the Macrocell is reset
to Read Mode. The data integrity of the Flash section where the Modify Operation has been terminated is
not guaranteed: The interrupted Flash Modify Operation must be repeated.
In general each Modify Operation is started through a sequence of 3 steps:
1. The first instruction is used to select the desired operation by setting its corresponding selection bit
in MCR (PGM or ERS) or UT0 (MRE or EIE).
2. The second step is the definition of the operands: the Address and the Data for programming or the
Sectors for erase or margin read.
3. The third instruction is used to start the Modify Operation, by setting EHV in MCR or AIE in UT0.
Once selected, but not yet started, one operation can be canceled by resetting the operation selection bit.
A summary of the available Flash Modify Operations are shown in the following Table 17-36.
Table 17-59. Flash Modify Operations
Operation
Double Word Program
Select bit
MCR.PGM
Operands
Address and Data by Interlock Writes
Start bit
MCR.EHV
Freescale Semiconductor
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
17-75