tmp1940cyaf TOSHIBA Semiconductor CORPORATION, tmp1940cyaf Datasheet - Page 406

• Manufacturer Part Number: tmp1940cyaf
• Description: 32-bit Tx System Risc Tx19 Family
• Manufacturer: TOSHIBA Semiconductor CORPORATION

3.5.14
3.5.15
as E5H and F6H. To calculate the checksum for a series of E5H and F6H:
Calculation of the Show Flash Memory Sum Command
provides the total sum as a halfword quantity. The sum is sent to the controller, with the upper eight bits
first, followed by the lower eight bits.
Checksum Calculation
the carries, and taking the two’s complement of the total sum. The Show Flash Memory Sum command
and the Show Product Information command perform the checksum calculation. The controller must
perform the same checksum operation in transmitting checksum bytes.
(1) Add the bytes together.
(2) Drop the carry.
(3) Take the two’s complement of the sum, and that is the checksum byte.
Table 3.12 Relationship between Received Bytes and Flash Memory Locations
Example:
Assume the Show Flash Memory Sum command provides the high- and low-order bytes of the sum
The Show Flash Memory Sum command adds all 512 Kbytes of the flash memory together and
The checksum byte for a series of bytes of data is calculated by adding the bytes together, dropping
E5H + F6H = 1DBH
0 – DBH = 25H
Example:
Received Byte
10th byte
11th byte
12th byte
13th byte
14th byte
15th byte
16th byte
5th byte
6th byte
7th byte
8th byte
9th byte
A1H
B2H
C3H
D4H
TMP1940FDBF-48
memory is four locations. Then the sum of the four bytes is
calcualted as:
For the interest of simplicity, assume the depth of the flash
A1H
Hence, 02H is first sent to the controller, followed by EAH.
Compared Flash Memory Data
Address 0x0000_03FA
Address 0x0000_03FB
Address 0x0000_03FC
Address 0x0000_03FD
Address 0x0000_03FE
Address 0x0000_03FF
B2H
Address 0x0000_03F4
Address 0x0000_03F5
Address 0x0000_03F6
Address 0x0000_03F7
Address 0x0000_03F8
Address 0x0000_03F9
C3H
D4H = 02EAH
TMP1940FDBF