CMIS upper pages register map (00h, 01h, 02h)

CMIS keeps its module-level static data in three upper pages: 00h the vendor identity block that hosts validate, 01h the advertising page that tells the host what the module can do and how long each step takes, and 02h the alarm/warning thresholds. This page lists them byte by byte, compiled against CMIS 5.x. Runtime bytes are in the CMIS lower page map; per-lane pages in the CMIS lane pages map.

Legend: rsvd = reserved · custom = vendor specific · all pages are selected with lower byte 127 (bank select is irrelevant for 00h–02h).

Page 00h — vendor identity, bytes 128–221 (covered by the page checksum)

Byte	Field	Contents
128	Identifier	as lower byte 0
129–144	Vendor name	16 ASCII, space padded
145–147	Vendor OUI	IEEE company ID
148–163	Vendor PN	16 ASCII
164–165	Vendor rev	2 ASCII
166–181	Vendor SN	16 ASCII
182–189	Date code	`YYMMDD` + 2 lot
190–199	CLEI code	10 ASCII (spaces if none)
200	Module power class	7–5 ModulePowerClass: 000 class 1 ≤ 1.5 W · 001 class 2 ≤ 3.5 W · 010 class 3 ≤ 7 W · 011 class 4 ≤ 8 W · 100 class 5 ≤ 10 W · 101 class 6 ≤ 12 W · 110 class 7 ≤ 14 W · 111 class 8 > 14 W · 4–0 rsvd
201	MaxPower	maximum power in units of 0.25 W (e.g. 30h = 12.0 W)
202	Cable assembly link length	7–6 LengthMultiplier: 00 ×0.1 m · 01 ×1 m · 10 ×10 m · 11 ×100 m · 5–0 BaseLength (0–63); 00h = not a cable assembly
203	Connector type	SFF-8024 Table 4-3 (0Ch MPO 1×12 · 07h LC · 23h no separable connector · 27h MPO 2×12 · 28h MPO 1×16)
204	Copper attenuation at 5 GHz	dB (cables)
205	Copper attenuation at 7 GHz	dB
206	Copper attenuation at 12.9 GHz	dB
207	Copper attenuation at 25.8 GHz	dB
208	Copper attenuation at 53.1 GHz	dB 5.1+
209	rsvd	—
210	Media lane information	bit n = 1: media lane n+1 not supported (unpopulated)
211	Cable assembly / far-end configuration	for cables: how the far end is arranged (single module, 2× / 4× / 8× breakout) per the CMIS far-end code table; 00h for transceivers
212	Media interface technology	00h 850 nm VCSEL · 01h 1310 nm VCSEL · 02h 1550 nm VCSEL · 03h 1310 nm FP · 04h 1310 nm DFB · 05h 1550 nm DFB · 06h 1310 nm EML · 07h 1550 nm EML · 08h other · 09h 1490 nm DFB · 0Ah copper unequalised · 0Bh copper passive equalised · 0Ch copper near & far end limiting active · 0Dh copper far end limiting · 0Eh copper near end limiting · 0Fh copper linear active · 10h C-band tunable laser · 11h L-band tunable laser · 12h–FFh rsvd/custom
213–221	rsvd	—
222	Page checksum	(Σ bytes 128–221) mod 256 — Checksums
223–255	Custom	vendor specific, not checksummed

Page 01h — advertising, bytes 128–255

Byte	Field	Contents
128	Inactive firmware — major	version of the standby image
129	Inactive firmware — minor	—
130	Hardware revision — major	—
131	Hardware revision — minor	—
132	SMF link length	7–6 multiplier: 00 ×0.1 km · 01 ×1 km · 5–0 base length
133	OM5 length	units of 2 m
134	OM4 length	units of 2 m
135	OM3 length	units of 2 m
136	OM2 length	units of 1 m
137	rsvd	—
138–139	Nominal wavelength	units of 0.05 nm
140–141	Wavelength tolerance	units of 0.005 nm
142	Supported pages and banks	bits advertise which page groups exist: banks implemented (0 only / 0–1 / 0–3), VDM pages 20h–2Fh, diagnostic pages 13h–14h, CDB pages 9Fh–AFh (bit assignment per revision)
143	Data-path durations	7–4 MaxDurationDPDeinit · 3–0 MaxDurationDPInit (nibble code below)
144	Module power durations	7–4 MaxDurationModulePwrDn · 3–0 MaxDurationModulePwrUp
145	Tx turn durations	7–4 MaxDurationDPTxTurnOff · 3–0 MaxDurationDPTxTurnOn
146–175	Module characteristics and controls advertising	cooling implemented, Tx/Rx polarity flip support, squelch and output-disable support, Tx input EQ ranges, Rx output EQ/amplitude ranges, CDR bypass support, aux monitor types (Aux1/2/3 = TEC current / laser temperature / Vcc2), supported flags and masks, signal-integrity control sets — byte positions per revision
176–190	Media lane assignment options, apps 1–15	one byte per application; bit n = 1: media lane n+1 may be the first media lane of the application
191–222	rsvd / custom	—
223–250	Application descriptors 9–15	4 bytes each, same layout as lower bytes 86–117
251–254	rsvd	—
255	Page checksum	(Σ bytes 130–254) mod 256 — bytes 128–129 (inactive firmware) are excluded because they change with updates

Duration nibble code (bytes 143–145)

Code	Max duration	Code	Max duration
0h	< 1 ms	7h	< 5 s
1h	< 5 ms	8h	< 10 s
2h	< 10 ms	9h	< 1 min
3h	< 50 ms	Ah	< 5 min
4h	< 100 ms	Bh	< 10 min
5h	< 500 ms	Ch	< 50 min
6h	< 1 s	Dh–Fh	rsvd

Hosts read these to size their bring-up timeouts — What the host does.

Page 02h — thresholds, bytes 128–255

Bytes	Threshold	Format
128–129 / 130–131 / 132–133 / 134–135	Temperature high alarm / low alarm / high warning / low warning	signed 16-bit, 1/256 °C
136–137 / 138–139 / 140–141 / 142–143	Vcc HA / LA / HW / LW	unsigned 16-bit, 100 µV
144–145 / 146–147 / 148–149 / 150–151	Aux1 HA / LA / HW / LW	as the Aux1 monitor
152–153 / 154–155 / 156–157 / 158–159	Aux2 HA / LA / HW / LW	as Aux2
160–161 / 162–163 / 164–165 / 166–167	Aux3 HA / LA / HW / LW	as Aux3
168–169 / 170–171 / 172–173 / 174–175	Custom monitor HA / LA / HW / LW	vendor
176–177 / 178–179 / 180–181 / 182–183	Tx power HA / LA / HW / LW	unsigned 16-bit, 0.1 µW
184–185 / 186–187 / 188–189 / 190–191	Tx bias HA / LA / HW / LW	unsigned 16-bit, 2 µA × multiplier (page 01h advertises ×1/×2/×4)
192–193 / 194–195 / 196–197 / 198–199	Rx power HA / LA / HW / LW	unsigned 16-bit, 0.1 µW
200–254	rsvd	—
255	Page checksum	(Σ bytes 128–254) mod 256

Lane thresholds apply to every lane; semantics in Thresholds & alarms.

Page 04h — laser capabilities (tunable modules)

Present when advertised; describes the supported grids (3.125 / 6.25 / 12.5 / 25 / 50 / 75 / 100 GHz and flex), the channel-number range per grid and the fine-tuning resolution and range. Channel setting and status live on page 12h — see Tunable maps and the lane pages map.

CMIS lower page map.
SFF-8636 upper pages map — the QSFP28 identity block for comparison.
Vendor fields — formatting rules for bytes 129–199.