Atmel AT88SA100S [DATASHEET]

9

8558F

−CRYPTO−9/11

5.1.1

Command Timing

After a command flag is transmitted, a command block should be sent to the chip. During parsing of the parameters and

subsequent execution of a properly received command, the chip will be busy and not respond to transitions on the signal pin.

The delays for these operations are listed in the table below:

Table 5-2.

Command Timing (Guaranteed by design; not tested)

Parameter

Symbol

Max

Unit

Notes

ParsingDelay

100

µs

Delay to check CRC and parse opcode and parameters before an

error indication will be available

MemoryDelay

3

ms

Delay to execute Read, Write and/or SramLock commands

FuseDelay

700

µs

Delay to execute BurnFuse command

See Section 6.3 for more details

MacDelay

30

ms

Delay to execute MAC command

PersonalizeDelay

13

ms

Delay to execute GenPersonalizationKey or LoadSram

5.1.2

Transmit Flag

The Transmit flag is used to turn around the signal so that the AT88SA100S can send data back to the system, depending on

its current state. The bytes that the AT88SA100S returns to the system, depending on its current state as follows:

Table 5-3.

Return Codes

State Description

Error/Status

Description

After Wake, but prior

to first command

0x11

Indication that a proper Wake token has been received by the AT88SA100S.

After successful

command execution

–

Return bytes per “Output Parameters” in Section 6, Commands of this document.

In some cases this is a single byte with a value of 0x00 indicating success. The

Transmit flag can be resent to the AT88SA100S repeatedly if a re-read of the

output is necessary.

Execution error

0x0F

Command was properly received but could not be executed by the AT88SA100S

chip. Changes in the AT88SA100S chip state or the value of the command bits

must happen before it is re-attempted.

After CRC or other

parsing error

0xFF

Command was not properly received by AT88SA100S and should be re-issued

by the system.

The AT88SA100S always transmits complete blocks to the system, so in the above table the status/error bytes result in 4-

bytes going to the system – count, error, CRC x 2.

Section 5.1.1). After this interval the system can send a transmit token to the AT88SA100S – if there was an error then the

AT88SA100S will respond with an error code. If there is no error then the AT88SA100S internally transitions automatically

5.1.3

Sleep Flag

The sleep flag is used to transition the AT88SA100S to the low power state, which causes a complete reset of the

AT88SA100S’ internal command engine and input/output buffer. It can be sent to the AT88SA100S at any time when the

AT88SA100S will accept a flag.