# ICODE SLIX2 Command Audit

**Date:** 2026-03-17
**Source:** SL2S2602 datasheet Rev 4.2, AN11809 Rev 1.2, SL2S2002 datasheet Rev 3.4

## Status

Commands marked OK are implemented in firmware native handler or response table.
Commands marked MISSING need implementation in the Python transponder model + table compiler.

### Standard ISO 15693 (firmware native handler)

| Cmd | Name | Status |
|-----|------|--------|
| 0x01 | INVENTORY | OK |
| 0x02 | STAY QUIET | OK |
| 0x20 | READ SINGLE BLOCK | OK (with lock_mode access control) |
| 0x21 | WRITE SINGLE BLOCK | OK (with lock_mode access control) |
| 0x22 | LOCK BLOCK | OK (firmware native) |
| 0x23 | READ MULTIPLE BLOCKS | OK |
| 0x25 | SELECT | OK |
| 0x26 | RESET TO READY | OK |
| 0x27 | WRITE AFI | OK (firmware native) |
| 0x28 | LOCK AFI | OK (firmware native) |
| 0x29 | WRITE DSFID | OK (firmware native) |
| 0x2A | LOCK DSFID | OK (firmware native) |
| 0x2B | GET SYSTEM INFO | OK |
| 0x2C | GET MULTIPLE BLOCK SECURITY | OK |

### NXP Custom Commands (table entries)

| Code | Name | Status | Priority | Notes |
|------|------|--------|----------|-------|
| 0xA0 | INVENTORY READ | OK | - | Like inventory but returns data blocks |
| 0xA1 | FAST INVENTORY READ | OK | - | Same as A0 at double data rate |
| 0xA2 | SET EAS | OK | - | Enables EAS mode (password protected) |
| 0xA3 | RESET EAS | OK | - | Disables EAS mode |
| 0xA4 | LOCK EAS | OK | - | Permanently locks EAS state |
| 0xA5 | EAS ALARM | OK | - | Returns 256-bit EAS sequence |
| 0xA6 | PASSWORD PROTECT EAS/AFI | OK | - | Enables password protection for EAS/AFI |
| 0xA7 | WRITE EAS ID | OK | - | Writes 16-bit EAS identifier |
| 0xAB | GET NXP SYSTEM INFO | OK | - | Returns PP, PP conditions, lock bits, feature flags |
| 0xB2 | GET RANDOM NUMBER | OK | - | Firmware native handler + Python model |
| 0xB3 | SET PASSWORD | OK | - | XOR password with GET_RANDOM, firmware + table entries |
| 0xB4 | WRITE PASSWORD | OK | - | Changes password value (requires prior SET PASSWORD) |
| 0xB5 | LOCK PASSWORD | OK | - | Permanently locks a password |
| 0xB6 | PROTECT PAGE | OK | - | Sets protection pointer + access conditions (requires write auth) |
| 0xB7 | LOCK PAGE PROTECTION | OK | - | Permanently locks protection config |
| 0xB9 | DESTROY | OK | - | Irreversibly kills tag (XOR password) |
| 0xBA | ENABLE PRIVACY | OK | - | Enters privacy mode (separate from SET PASSWORD, XOR password) |
| 0xBB | 64-BIT PASSWORD PROTECTION | OK | - | Requires both R+W passwords |
| 0xBC | STAY QUIET PERSISTENT | OK | - | Persistent quiet survives power cycles |
| 0xBD | READ SIGNATURE | OK | - | Returns 32-byte ECC originality signature |

### Model Issues

1. ~~**Password ID 0x10 (EAS/AFI) missing**~~ — FIXED: pwd_id 0x10 now in model.

2. ~~**Privacy mode behavior**~~ — FIXED: GET_RANDOM now works in privacy mode.

3. ~~**ENABLE PRIVACY (0xBA) is separate**~~ — FIXED: 0xBA implemented as dedicated command with XOR password.

4. ~~**16-bit counter (block 79)**~~ — FIXED: `BlockAccess.write_mode="counter"` in memory model, LE16 increment with 0xFFFF saturation.

5. **Protection pointer access conditions** — datasheet defines Page L / Page H with separate read/write protection bits (Extended Protection Status byte). Model uses simpler `protection_pointer` integer.

6. ~~**CC byte 3 MBREAD flag missing**~~ — FIXED: NFC Type 5 CC byte 3 was `0x00` (no MBREAD), causing phones to never send READ MULTIPLE BLOCKS. Real SLIX2 tags advertise `0x01` (MBREAD supported). Without this flag, Android NFC reads CC + system info then gives up — it won't fall back to READ SINGLE BLOCK for NDEF data. Fixed in `NfcType5Tag._write_cc()` for all Type 5 tags.

### Implementation Priority

**Completed (2026-03-17):**
1. ~~GET NXP SYSTEM INFO (0xAB)~~ — model + table compiler
2. ~~READ SIGNATURE (0xBD)~~ — model + table compiler
3. ~~ENABLE PRIVACY (0xBA)~~ — model + table compiler
4. ~~EAS/AFI password (pwd_id 0x10)~~ — model + table compiler
5. ~~PROTECT PAGE (0xB6)~~ — model (write auth required)
Also: Fixed 0xA1/0xA2 names (FAST INVENTORY READ / SET EAS), removed fake config registers,
fixed privacy mode to allow GET_RANDOM, SET_PASSWORD uses XOR with GET_RANDOM.

**Completed (2026-03-18):**
6. ~~WRITE PASSWORD (0xB4)~~ — model (requires prior SET PASSWORD auth, XOR password)
7. ~~LOCK PASSWORD (0xB5)~~ — model (permanently locks password, prevents WRITE PASSWORD)
8. ~~DESTROY (0xB9)~~ — model (irreversibly kills tag, XOR password, no prior auth)
9. ~~LOCK PAGE PROTECTION (0xB7)~~ — model (permanently locks PP config, requires write auth)
10. ~~64-BIT PASSWORD PROTECTION (0xBB)~~ — model (requires both read + write auth)

**Completed (2026-03-18):**
11. ~~EAS subsystem (0xA2-0xA7)~~ — SET/RESET/LOCK EAS, EAS ALARM, PASSWORD PROTECT EAS/AFI, WRITE EAS ID
12. ~~INVENTORY READ / FAST INVENTORY READ (0xA0/0xA1)~~ — returns UID + block data
13. ~~STAY QUIET PERSISTENT (0xBC)~~ — survives power cycles

**Completed (2026-03-18):**
14. ~~Block 79 counter~~ — `write_mode="counter"` in BlockAccess, LE16 increment with saturation at 0xFFFF

**All SLIX2 commands implemented.** No remaining gaps.

### Cross-IC Command Scope (2026-03-18)

Full transponder audit against datasheets (SL2S2002, SL2S3003, SL2S6002, NTP5210, NTA5332, AN11809) found command scope issues in the class hierarchy:

1. **SLIX (SL2S2002) had 3 excess commands** — 0xAB (GET NXP SYSTEM INFO), 0xBD (READ SIGNATURE), 0xA7 (WRITE EAS ID) were dispatched at the SLIX/NxpIcodeTag level but are SLIX2+ only per SL2S2002 datasheet and AN11809. Moved dispatch to IcodeSlix2Tag.

2. **NTAG 5 had STAY QUIET PERSISTENT (0xBC) but shouldn't** — inherited from IcodeSlix2Tag. NTP5210 and NTA5332 datasheets omit it; feature flags confirm PERS_QUIET=0b. Blocked at Ntag5PlatformTag.

3. **NTAG 5 was missing WRITE SRAM (0xD3)** — NTA5332 Table 122 lists it. Added to Ntag5LinkTag.

4. **NTAG 5 was missing AREA_1 password IDs (0x40/0x80)** — NTP5210/NTA5332 datasheets list these. Added to Ntag5PlatformTag.

5. **NTAG 5 was missing PICK RANDOM UID (0xC2)** — NTA5332 datasheet 8.2.4.9.15. Added to Ntag5PlatformTag (AES mode).

See `docs/plans/2026-03-18-transponder-audit-fixes.md` for full audit plan.