Compiled specifications
| Parameter | Value |
|---|---|
| Part number | HSEMSDY9S2B64G |
| Density / capacity | 64 GB (3D TLC, 512 Gb × 1) |
| Speed / grade | eMMC 5.1, HS400 up to 200 MHz (SDR/DDR, 1/4/8-bit) |
| Supply voltage | VCC 2.7-3.6 V (typ 3.3 V); VCCQ 1.7-1.95 V (typ 1.8 V) or 2.7-3.6 V (typ 3.3 V) |
| Operating temperature | -25°C to +85°C (operating); -40°C to +85°C (storage) per manufacturer datasheet |
| Product line | Consumer eMMC 5.1 |
| Typical applications | Mobile phone, tablet, smart TV, set-top box, networking appliance (manufacturer's own list) |
| Lifecycle | Active |
Blank rows are omitted rather than filled with a guess.
What this part is
HSEMSDY9S2B64G is HIKSEMI’s 64 GB consumer eMMC 5.1 device: a single 3D TLC die (512 Gb × 1) paired with an embedded thin-flash controller in a 153-ball FBGA measuring 11.5 × 13 × 1.0 mm. JEDEC/MMC standard version 5.1 compliant, backward compatible to eMMC v4.5 through v5.1. The manufacturer positions it for embedded use in mobile phones, tablets, smart TVs, set-top boxes and networking appliances. Every figure below comes from one document, identified in full near the end of this page.
Who makes it. HIKSEMI is the storage brand of 杭州海康存储科技有限公司 (Hangzhou HIKStorage Technology Co., Ltd.). The company’s own profile states it was founded in 2017 and builds on the technology base of Hikvision (海康威视) in audio-video, imaging capture and data management, with its timeline putting the engineering team at 2015 and the registered company at 2017. The datasheet behind this page carries that same entity’s copyright line, so brand and document author are one party here.
Capacity map as delivered
The device ships with a user data area, two boot area partitions and an RPMB partition. Boot partition sizes are fixed; the user area is what a firmware image actually sees.
| Item | Value (64 GB) |
|---|---|
| User area capacity | 59,648 MB |
| SEC_COUNT in Extended CSD | 0x7480000 |
| Boot partition 1 / 2 | 4,096 KB each |
| Maximum enhanced user area | 19,872 MB (0x4DA × 0x20 × 0x1 × 512 KB) |
| Pre-burned capacity (FOB state) | 19.4 GB |
| Reflow tolerance | 3 times |
MemSignal recomputed rather than transcribed: SEC_COUNT 0x7480000 is 122,159,104 sectors of 512 bytes, which is exactly 59,648 MB, and the enhanced-area row reproduces the manufacturer’s own formula (MAX_ENH_SIZE_MULT × HC_WP_GRP_SIZE × HC_ERASE_GRP_SIZE × 512 KB) to the megabyte. Pre-burned capacity is the data budget available before SMT: anything written to the device ahead of reflow has to stay inside it.
Interface
- Bus width 1-bit (default), 4-bit or 8-bit; Single Data Rate and Dual Data Rate supported.
- Top timing mode HS400, clock 0 to 200 MHz.
- Protocol JEDEC/MMC standard version 5.1; backward compatible to eMMC v4.5 through v5.1.
- Package: 153-ball FBGA, 11.5 × 13 × 1.0 mm.
- Registers as printed by the manufacturer: CID product name SDY9S2, product revision 0x10, Extended CSD revision 0x08.
Supply and power
VCC (NAND/core) is 2.7 to 3.6 V, typical 3.3 V. VCCQ (controller/IO) accepts either 1.7 to 1.95 V (typical 1.8 V) or 2.7 to 3.6 V (typical 3.3 V), so the board is designed for one I/O rail or the other, not both at once.
| Operation | Icc (mA, max) | Iccq (mA, max) |
|---|---|---|
| Read | 115 | 110 |
| Write | 110 | 90 |
Standby draws 65 µA on VCC and 140 µA on VCCQ; in sleep, VCC drops to 0 µA while VCCQ stays at 140 µA (both with an 8-bit bus and no clock, sleep entered by CMD5 with VCC switched off). Maximum RMS current is averaged over a 100 ms window, and the manufacturer notes these figures are “not 100% tested”. One gap worth naming: this document does not state which timing mode Table 11 was measured in, so its currents cannot be compared mode-for-mode against another part’s current table.
Performance figures
Sequential read up to 320 MB/s and write up to 280 MB/s; random read up to 5,300 IOPS and random write up to 3,900 IOPS, all at HS400. The manufacturer publishes its test conditions, and the two tables do not share them: the sequential pair was measured on a GL3227 card reader over USB 3.0 on an exFAT volume in a clean state using CDM 7.0.0, while the random pair used the same reader and bus on FAT32 with an OS-less host. These are component-level vendor figures, not system benchmarks; they will not reproduce on a different host controller, file system or fill state.
Device features listed by the manufacturer
From the same document’s feature overview: original and alternative boot modes; hardware reset signal; data removal commands (erase, trim, sanitize, discard); multiple partitioning; signed access to a replay protected memory block (RPMB); lock/unlock and write protection; password, permanent, power-on and temporary data protection mechanisms; sleep and awake modes; and power-off notification. Nothing outside that list is claimed for the device by this document — it does not list field firmware update, and the document’s own Extended CSD table gives FFU_FEATURES as 0x00.
Temperature, and what the document does not claim
The manufacturer states an operating temperature range of -25°C to +85°C and a storage temperature range of -40°C to +85°C. Note the asymmetry: the storage range reaches lower on the cold side than the operating range, so -40°C is a handling figure, not a condition this device is specified to run at. MemSignal files this part under the extended consumer band because that is the range printed in the document and because the document titles itself a consumer part.
What the document does not contain is as informative as what it does. There is no qualification or certification statement of any kind in it, no grade designation, no endurance figure (P/E cycles or terabytes written), no reliability or RoHS/moisture-sensitive statement, and no lifecycle or end-of-life position. It exposes a Pre-EOL information register field whose meaning the document itself does not define. Anyone reading this page for an automotive or industrial design-in should treat those absences as real: this is a consumer-grade datasheet, and nothing here substitutes for the manufacturer’s own qualification document.
Compared with the manufacturer’s public 64 GB consumer part
The manufacturer’s public Consumer eMMC document list carries a different 64 GB part, HSEMSDS7S2B64G (datasheet V2.0). It shares the capacity, the package dimensions, the 153-ball count, the user area, the SEC_COUNT value, the pre-burned budget and the temperature ranges with HSEMSDY9S2B64G, and differs everywhere a change of NAND build would show up:
One correction we made after publishing this comparison: the other part’s NAND figure is not as settled as the row below first implied. The manufacturer’s own two documents for HSEMSDS7S2B64G state different die counts, which is why that cell now defers to that part’s page instead of quoting one number. Every other row here is unaffected — those figures are identical in both of that part’s documents.
| Attribute | HSEMSDY9S2B64G (this page) | HSEMSDS7S2B64G (public) |
|---|---|---|
| NAND build | 3D TLC, 512 Gb × 1 | stated as 256 Gb × 2 in the public datasheet and as 512 Gb × 1 in a channel copy of the same part number — see that part’s page |
| Sequential read / write | up to 320 / 280 MB/s | up to 270 / 210 MB/s |
| Random read / write | up to 5,300 / 3,900 IOPS | up to 4,000 / 2,800 IOPS |
| Read current Icc / Iccq | 115 / 110 mA | 95 / 100 mA |
| Write current Icc / Iccq | 110 / 90 mA | 80 / 85 mA |
| Standby current Icc / Iccq | 65 / 140 µA | 10 / 75 µA |
| Maximum enhanced user area | 19,872 MB (0x4DA × 0x20 × 0x1) | 19,880 MB (0x9B5 × 0x10 × 0x1) |
| Identical in both documents | user area 59,648 MB · SEC_COUNT 0x7480000 · boot partitions 4,096 KB × 2 · pre-burned 19.4 GB / 3 reflows · package 11.5 × 13 × 1.0 mm, 153 balls · temperature ranges | |
MemSignal also compared the two documents’ ball-assignment tables entry by entry: all 153 balls match, so the two parts look identical on a schematic and in a footprint. That is not a fit assessment. The performance and current figures above are not the same, the NAND build is not the same, and a substitution decision needs an engineering review of firmware behaviour and endurance with a named reviewer per row — which this site publishes only when that review exists (see Cross-references below).
Source and status of this document
The underlying document is “HIKSEMI Consumer eMMC5.1 HSEMSDY9S2B64G DataSheet V1.0”, 22 pages. Its revision history has a single row: version 1.0, dated Feb.26th, 2025, described as “Preliminary”, and the closing notice reads “Data subject to change without notice”. The copyright line says 2020 and the page footers point at en.hikstorage.com, the manufacturer’s legacy domain, while its product pages live at hiksemitech.com. The file’s own creation timestamp is 2025-09-28, seven months after the revision date it declares.
This part number is not on the manufacturer’s public Consumer eMMC document list as MemSignal last checked it, on 2026-10-06; that list carries HSEMSDW5F2B256G, HSEMSDS7D2B128G and HSEMSDS7S2B64G. We have since widened that check to the manufacturer’s Chinese consumer eMMC page, whose model list names five parts — HSEMSBS3S2B08G, HSEMSES2S2B16G, HSEMSDS6S2B32G, HSEMSDS7S2B64G and HSEMSDS7D2B128G — and this part number appears on neither list, so the gap is not a translation artefact. The copy behind this page reached us through the supply chain rather than from the manufacturer’s website, so MemSignal neither links to it nor hosts it. The parameters above are the manufacturer’s stated values as printed in that preliminary document. Anyone designing in this part should obtain the current release from the manufacturer or from their own supplier and check it against this page before committing.
Ordering code and availability status
The manufacturer’s part number HSEMSDY9S2B64G is the ordering code: the document contains no ordering-information, marking or part-number-system section (checked against the full text — “ordering”, “marking” and “top mark” appear nowhere in it), and our own distribution desk orders against the manufacturer part number rather than a separate internal code. Confirmed internally on 2026-10-06.
Lifecycle is marked Active on the same basis: it is the status reported by our distribution desk as of 2026-10-06, which stocks and sells this device. This is the one value on the page that the manufacturer’s document does not print — the datasheet takes no lifecycle or end-of-life position, and no manufacturer statement of production status was available to us. Treat it as a distributor’s current status, dated, not as a factory lifecycle notice; if a design depends on long-term supply, ask the manufacturer for a written product-status statement through your own contact.
Not yet recorded
No source behind this page states a country of origin for the part, so that field stays empty rather than being inferred from the company’s registration address. Endurance figures (P/E cycles, terabytes written) are absent from the document and are therefore not published here. Cross-referenced alternatives are gated on this page for the same reason as every other part: a substitution row would change what somebody buys, so it needs a source, a date and a named reviewer first.
Cross-references & alternatives
A cross-reference here would change what a customer buys. We publish one only when each row carries a source and a date and has been checked by a named reviewer.
- Table shape: Alternative · Fit · Differs in · Source · Checked
- Blocked on: an engineering review step with a named reviewer per row
Official documentation
MemSignal does not host, reproduce or distribute datasheets. Where the manufacturer publishes one, we link to it.
Provenance
- Source: HIKSEMI "Consumer eMMC5.1 HSEMSDY9S2B64G DataSheet" V1.0, single revision row 1.0 Preliminary dated 2025-02-26, received through the distribution channel (PDF md5 b1c2b3577f41bcc98754d06854683f1e); this SKU is not on the manufacturer's public Consumer eMMC document list as of 2026-10-06, so no datasheet link is published. Comparison column from the manufacturer's public "HIKSEMI 64GB eMMC5.1 HSEMSDS7S2B64G DataSheet V2.0" on hiksemitech.com. Ordering code and Active lifecycle: our distribution desk, confirmed 2026-10-06 (not stated in the manufacturer's document).
- Checked: 2026-10-06
Cross-reference and substitution advice appear only where each claim carries a source and a date.
Parameters not compiled for this part
- Country of origin
Listed so the gap is visible on the page, not inferred later.
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