cp3bt13 National Semiconductor Corporation, cp3bt13 Datasheet - Page 33

• Manufacturer Part Number: cp3bt13
• Description: Cp3bt13 Reprogrammable Connectivity Processor With Bluetooth-r And Can Interfaces
• Manufacturer: National Semiconductor Corporation

8.2.1
Main Block 0 and Main Block 1 hold the 256K-byte program
space, which consists of the Boot Area and Code Area.
Each block consists of sixteen 8K-byte sections. Write ac-
cess by the CPU to Main Block 0 and Main Block 1 is con-
trolled by the corresponding bits in the FM0WER and
FM1WER registers, respectively. The least significant bit in
each register controls the section at the lowest address.
8.2.2
Information Block 0 contains 128 bytes, of which one 16-bit
word has a dedicated function, called the Function Word.
The Function Word resides at address 07Eh. It holds factory
parameters.
Software only has read access to Information Block 0
through a register-based interface. The Function Word and
the factory parameters are protected against CPU writes.
Table 14 shows the structure of Information Block 0.
8.2.3
Information Block 1 contains 128 bytes, of which one 16-bit
word has a dedicated function, called the Protection Word.
The Protection Word resides at address 0FEh. It controls
the global protection mechanisms and the size of the Boot
Area. The Protection Word can be written by the CPU, how-
ever the changes only become valid after the next device re-
set. The remaining Information Block 1 locations can be
used to store other user data. Erasing Information Block 1
also erases Main Block 1. Table 15 shows the structure of
the Information Block 1.
8.2.4
Main Block 2 holds the 8K-byte data area, which consists of
sixteen 512-byte sections. Write access by the CPU to Main
Block 2 is controlled by the corresponding bits in the
FSM0WER register. The least significant bit in the register
controls the section at the lowest address.
Other (Used
Parameters)
(User Data)
for Factory
Protection
Function
Name
Name
Other
Word
Word
Information Block 0
Information Block 1
Main Block 0 and 1
Main Block 2
Table 14 Information Block 0
Table 15 Information Block 1
0FEh
07Eh
000h
080h
Address
Address
Range
Range
–0
–0
–0
–0
7Dh
FDh
7Fh
FFh
Access
Access
Read
Read
Yes
Yes
Write access only
protection is dis-
and global write
enable bit is set
Write Access
Write Access
if section write
abled.
No
33
8.2.5
Information Block 2 contains 128 bytes, which can be used
to store user data. The CPU can always read Information
Block 2. The CPU can write Information Block 2 only when
global write protection is disabled. Erasing Information
Block 2 also erases Main Block 2.
8.3
Flash memory programming (erasing and writing) can be
performed on the flash data memory while the CPU is exe-
cuting out of flash program memory. Although the CPU can
execute out of flash data memory, it cannot erase or write
the flash program memory while executing from flash data
memory. To erase or write the flash program memory, the
CPU must be executing from the on-chip static RAM or off-
chip memory.
An erase operation is required before programming. An
erase operation sets all of the bits in the erased region. A
programming operation clears selected bits.
The programming mechanism is pipelined, so that a new
write request can be loaded while a previous request is in
progress. When the FMFULL bit in the FMSTAT or FSM-
STAT register is clear, the pipeline is ready to receive a new
request. New requests may be loaded after checking only
the FMFULL bit.
8.3.1
Read accesses from flash program memory can only occur
when the flash program memory is not busy from a previous
write or erase operation. Read accesses from the flash data
memory can only occur when both the flash program mem-
ory and the flash data memory are not busy. Both byte and
word read operations are supported.
8.3.2
Information block data is read through the register-based in-
terface. Only word read operations are supported and the
read address must be word-aligned (LSB = 0). The following
steps are used to read from an information block:
8.3.3
A flash erase operation sets all of the bits in the erased re-
gion. Pages of a main block can be individually erased if
their write enable bits are set. This method cannot be used
to erase the boot area, if defined. Each page in Main Block
0 and 1 consists of 1024 bytes (512 words). Each page in
Main Block 2 consists of 512 bytes (256 words). To erase a
page, the following steps are performed:
1. Load the word address in the Flash Memory Informa-
2. Read the data word by reading out the Flash Memory
1. Verify that the Flash Memory Busy (FMBUSY) bit is
2. Prevent accesses to the flash memory while erasing is
tion Block Address (FMIBAR) or Flash Slave Memory
Information Block Address (FSMIBAR) register.
Information Block Data (FMIBDR) or Flash Slave Mem-
ory Information Block Data (FSMIBDR) register.
clear. The FMBUSY bit is in the FMSTAT or FSMSTAT
register.
in progress.
Information Block 2
FLASH MEMORY OPERATIONS
Main Block Read
Information Block Read
Main Block Page Erase
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