DS87000 Datasheet, PDF (4/10 Pages) Dallas Semiconductor – Microcontroller Programmer

DS87000
Edit
This command provides full screen edit capability of the programmer’s encryption vector. All bytes of the
vector are displayed on the screen, and each can be individually edited. The vector is presented in hex format
in the center of the screen, and the ASCII representation is to the right. If the hex value cannot be represented
in printable ASCII, a period (.) is displayed. The cursor may be placed over either the hex or ASCII value and
a new value entered. When exiting the edit function after modifying one or more bytes of the vector, the user
will be asked if the changes are to be saved. If yes, the new vector will be stored in the programmer.
The user may clear the entire encryption vector by entering an ALT-C. Note that a cleared encryption vector
is all ones, and if a cleared vector is stored in the device, there will be no encryption. A series of random
numbers will be used to fill the encryption vector if an ALT-R is entered. A randomly selected encryption
vector provides a more secure device.
DEVICE MENU
Blank Check
This command reads the device to confirm that it is completely erased (all 1’s). The user is prompted to enter
the beginning and ending address of the range to be checked. The default range is displayed, and may be
modified or accepted as is.
Read
This command will read all or part of the device's EPROM and store it in the programmer's buffer memory.
The user is prompted to enter the beginning and ending address of the range to be read. The default range is
displayed, and may be modified or accepted as is.
If an encryption vector has been stored in the device, the data will be encrypted as it is read. If the intent is to
read non-encrypted data, the read must be performed before the encryption array is written to the device. The
lock bits also have an effect on this function. If either of the two highest levels of lock are written to the
device, the data read will be all ones.
Verify
Verify that the device's EPROM contains the same information as the programmer's buffer. The user is
prompted to enter the beginning and ending address of the range to be verified. The default range is
displayed, and may be modified or accepted as is.
Since the verify function actually reads data from the device, verify must be performed before the device’s
encryption array, lock bits, and/or serial number are written. After the encryption array is written to the
device, all data that is read will be encrypted as a standard function of this security measure. After the lock
bits are written, it may not be possible to read the device at all, depending on the level of lock. The serial
number is unique for every device programmed, so it will not verify from one device to another.
IBlank Check
This command reads the device to confirm that it can be programmed with the contents of the buffer. This
mode makes use of the fact that a completely blank device is not required for proper programming. For
instance, if the device contains a 0 bit where a 0 bit is to be programmed, then it does not matter that the bit
is not "blank" (i.e., 1). Also, if a byte already contains the byte to be programmed, then it does not need to be
re-programmed, and it does not matter that it is not blank. The user is prompted to enter the beginning and
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