Information

28.4.10.4 Read Resource Command
The Read Resource command allows the user to read data from special-purpose memory
resources located within the FTFL module. The special-purpose memory resources
available include program flash IFR space and the Version ID field. Each resource is
assigned a select code as shown in Table 28-37.
Table 28-36. Read Resource Command FCCOB Requirements
FCCOB Number FCCOB Contents [7:0]
0 0x03 (RDRSRC)
1 Flash address [23:16]
2 Flash address [15:8]
3 Flash address [7:0]
1
Returned Values
4 Read Data [31:24]
5 Read Data [23:16]
6 Read Data [15:8]
7 Read Data [7:0]
User-provided values
8 Resource Select Code (see Table 28-37)
1. Must be longword aligned (Flash address [1:0] = 00).
Table 28-37. Read Resource Select Codes
Resource
Select Code
Description Resource Size Local Address Range
0x00 IFR 256 Bytes 0x0000 - 0x00FF
0x01
1
Version ID 8 Bytes 0x0000 - 0x0007
1. Located in program flash 0 reserved space; Flash address [23] = 0
After clearing CCIF to launch the Read Resource command, four consecutive bytes are
read from the selected resource at the provided relative address and stored in the FCCOB
register. The CCIF flag sets after the Read Resource operation completes. The Read
Resource command exits with an access error if an invalid resource code is provided or if
the address for the applicable area is out-of-range.
Table 28-38. Read Resource Command Error Handling
Error Condition Error Bit
Command not available in current mode/security FSTAT[ACCERR]
An invalid resource code is entered FSTAT[ACCERR]
Table continues on the next page...
Flash Operation in Low-Power Modes
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
630 Freescale Semiconductor, Inc.