One Way Passcode Service

Provides a mechanism for overriding the software debug lock SWL_DEBUG without requiring any interaction with an external intelligence. This service is similar to One-Time Passcode but has selective unlocking capability and does not require a FPGA nonce.

Table 1. One Way Passcode Service Request
System Service Descriptor Bit Field Value Description
15:7 MBOXADDR[10:2] Mailbox address.
6:0 7DH One-way Passcode service command.

The following table lists the One Way Passcode service mailbox format.

Table 2. One Way Passcode Service Mailbox Format
Offset Length (bytes) Parameter Direction Description
0 16 MSG ID Input Message identification
16 32 V Input Input Validator
48 2 BSVER Input Not used. Value Ignored
50 1 CTYPE Input
51 1 KEYMODE Input
52 16 UID Input Not used. Value Ignored1
68 16 DSN Input
84 256 USERDATA Input Not used. Value Ignored1
340 1 OPTIONS Input
341 1 RESERVED Input Reserved
342 2 SWVER Input Not used. Value Ignored1
344 8 RESERVED Input Reserved
352 32 HASH Input Hash of next 96 bytes
384 32 Plaintext Passcode Input Encrypted via bitstream mechanism
416 16 HWM Input Encrypted via bitstream mechanism
432 8 LOCKMASK Input Encrypted via bitstream mechanism

Not used. Value Ignored1

SWL_DEBUG always chosen.

440 1 PCYTPE Input Encrypted via bitstream mechanism

Not used. Value Ignored1

PCTYPE=1 DPK always chosen.

441 7 RESERVED Input Reserved
448 32 TNEXT Input Not used. Value Ignored1
(1) Value of 0 must be used for value ignored.