saf-xc866-4rri3v Infineon Technologies Corporation, saf-xc866-4rri3v Datasheet - Page 45

• Manufacturer Part Number: saf-xc866-4rri3v
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Infineon Technologies Corporation

3.3.2
For the P-Flash banks, a programmed wordline (WL) must be erased before it can be
reprogrammed as the Flash cells can only withstand one gate disturb. This means that
the entire sector containing the WL must be erased since it is impossible to erase a
single WL.
For the D-Flash bank, the same WL can be programmed twice before erasing is required
as the Flash cells are able to withstand two gate disturbs. Hence, it is possible to
program the same WL, for example, with 16 bytes of data in two times (see
Figure 12
Note: When programming a D-Flash WL the second time, the previously programmed
Data Sheet
0000 ….. 0000
0000 ….. 0000
1111 ….. 0000
Flash memory cells (whether 0s or 1s) should be reprogrammed with 0s to retain
its original contents and to prevent “over-programming”.
Flash memory cells
Flash Programming Width
32 bytes (1 WL)
D-Flash Programming
H
H
H
0000 ….. 0000
1111 ….. 1111
1111 ….. 1111
H
H
H
Program 1
Program 2
41
0000 ….. 0000
1111 ….. 0000
Note: A Flash memory cell can be programmed
16 bytes
32-byte write buffers
from 0 to 1, but not from 1 to 0.
Functional Description
H
H
1111 ….. 1111
0000 ….. 0000
16 bytes
V1.2, 2007-10
Figure
XC866
H
H
12).