Datasheet

Data Sheet ADuC7019/20/21/22/24/25/26/27/28/29
Rev. F | Page 53 of 104
Table 35. FEECON Register
Name Address Default Value Access
FEECON 0xFFFFF808 0x07 R/W
FEECON is an 8-bit command register. The commands are
described in Table 36.
Table 36. Command Codes in FEECON
Code Command Description
0x00
1
Null Idle state.
0x01
1
Single read
Load FEEDAT with the 16-bit data.
Indexed by FEEADR.
0x02
1
Single write Write FEEDAT at the address pointed to
by FEEADR. This operation takes 50 µs.
0x03
1
Erase/write Erase the page indexed by FEEADR and
write FEEDAT at the location pointed by
FEEADR. This operation takes approxi-
mately 24 ms.
0x04
1
Single verify Compare the contents of the location
pointed by FEEADR to the data in
FEEDAT. The result of the comparison is
returned in FEESTA, Bit 1.
0x05
1
Single erase Erase the page indexed by FEEADR.
0x06
1
Mass erase Erase 62 kB of user space. The 2 kB of
kernel are protected. This operation
takes 2.48 sec. To prevent accidental
execution, a command sequence is
required to execute this instruction.
See the Command Sequence for
Executing a Mass Erase section.
0x07 Reserved Reserved.
0x08 Reserved Reserved.
0x09 Reserved Reserved.
0x0A Reserved Reserved.
0x0B Signature Give a signature of the 64 kB of Flash/EE
in the 24-bit FEESIGN MMR. This
operation takes 32,778 clock cycles.
0x0C Protect This command can run only once. The
value of FEEPRO is saved and removed
only with a mass erase (0x06) of the key.
0x0D Reserved Reserved.
0x0E Reserved Reserved.
0x0F Ping No operation; interrupt generated.
1
The FEECON register always reads 0x07 immediately after execution of any
of these commands.
Table 37. FEEDAT Register
Name Address Default Value Access
FEEDAT 0xFFFFF80C 0xXXXX
1
R/W
1
X = 0, 1, 2, or 3.
FEEDAT is a 16-bit data register.
Table 38. FEEADR Register
Name Address Default Value Access
FEEADR 0xFFFFF810 0x0000 R/W
FEEADR is another 16-bit address register.
Table 39. FEESIGN Register
Name Address Default Value Access
FEESIGN 0xFFFFF818 0xFFFFFF R
FEESIGN is a 24-bit code signature.
Table 40. FEEPRO Register
Name Address Default Value Access
FEEPRO 0xFFFFF81C 0x00000000 R/W
FEEPRO MMR provides protection following a subsequent
reset of the MMR. It requires a software key (see Table 42).
Table 41. FEEHIDE Register
Name Address Default Value Access
FEEHIDE 0xFFFFF820 0xFFFFFFFF R/W
FEEHIDE MMR provides immediate protection. It does not
require any software key. Note that the protection settings in
FEEHIDE are cleared by a reset (see Table 42).
Table 42. FEEPRO and FEEHIDE MMR Bit Designations
Bit Description
31 Read protection. Cleared by user to protect all code.
Set by user to allow reading the code.
30:0 Write protection for Page 123 to Page 120, Page 119
to Page 116, and Page 0 to Page 3. Cleared by user to
protect the pages from writing. Set by user to allow
writing the pages.
Command Sequence for Executing a Mass Erase
FEEDAT=0x3CFF;
FEEADR = 0xFFC3;
FEEMOD= FEEMOD|0x8; //Erase key enable
FEECON=0x06; //Mass erase command