XC2200 Derivatives
System Units (Vol. 1 of 2)
Memory Organization
User’s Manual
3-20
V2.1, 2008-08
MemoryX2K, V1.3
Figure 3-5
Flash Structure
3.9.2
Operating Modes
The IMB and the flash memory and each flash module have certain modes of operation.
Some modes define clocking and power supply and the operating state of the analog
logic as oscillators and voltage pumps. Overall system modes (e.g. startup mode)
influence the behavior or the flash memory as well.
Other modes define the functional behavior. These will be discussed here.
3.9.2.1
Standard Read Mode
After reset and after performing a clean startup the flash memory with all its modules is
in “standard read mode”. In this mode it behaves as an on-chip ROM. This mode is
entered:
•
After reset when the complete start-up has been performed.
•
After completion of a longer lasting command like “erase” or “program” which is
acknowledged by clearing the “busy” flag.
•
Immediately after each other command execution.
flash_array_userview_diagram.vsd
256 KB
Array
Sector
Number
0
1
2
63
Sector
Page
Number
0
1
2
31
Page
Block
Num ber
0
1
2
7
Sector
Page
Block
137 Bits
9 Bits ECC
128 Bits Data
Combined flash memory byte address
Array
[1:0]
[ ][
][
][
][
]
.. . . . . . . . . . . . . . . . . . .
Sector
[5:0]
Page
[4:0]
Block
[2:0]
Byte
[3:0]