at88sc0104c ATMEL Corporation, at88sc0104c Datasheet - Page 36

• Manufacturer Part Number: at88sc0104c
• Description: Cryptomemory Specification For Standard Mode Of Operation
• Manufacturer: ATMEL Corporation

7.6.4
7.6.4.1
7.6.4.2
7.6.4.3
32
AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
System Read : $B6
Functional
Read Config Zone
Read Fuse Byte
Number of Bytes N
Read Command
Figure 7-9.
The System Read command allows reading of system data from the device. Depending on the
value of address 1, the host may read the data in the configuration memory, or the fuses.
Table 7-6.
The data byte address to be read is defined by address 2 in the command and is internally incre-
mented following the transmission of each data byte. The value N defines how many bytes
CryptoMemory will read, a value of zero will result in 256 bytes read. If the address provided is
an unauthorized address, the device will not ACK the N byte and will not return any data. Since
access rights vary throughout the configuration zone, the host may provide an authorized start-
ing address and a number of bytes N that causes the device to reach unauthorized address. In
this case the device will transmit the fuse byte (see below) in place of unauthorized bytes.
Fuse data is returned in the form of a single byte. Bits 0 to 3 represent the fuse states, a value
of ‘0’ indicates the fuse has been blown. Bits 4 to 7 are not used as security fuses and are
reserved by Atmel.
Figure 7-10. Read Fuse Bytes
Command Description
Read Config Zone
Read Fuse Byte
Address 1
Address 2
resv
F
Host
7
System Read Command Functional Description
System Read Command Description
resv
F
6
resv
F
5
Device
Command
resv
Data
Data
F
...
$B6
$B6
4
SEC
F
3
Addr 1
$00
$01
N data bytes
PER
F
2
Addr 2
CMA
addr
F
$00
1
5210A–SMIC–04/07
FAB
F
$01
0
N
N