1、JEDEC SOLID STATE TECHNOLOGY ASSOCIATIONJEDECSTANDARDJESD84-C44JULY 2009Embedded MultiMediaCard (eMMC) Mechanical Standard, with Optional Reset SignalNOTICEJEDEC standards and publications contain material that has been prepared, reviewed, andapproved through the JEDEC Board of Directors level and s
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9、limited number of copies through entering into a license agreement. For information, contact:JEDEC Solid State Technology Association3103 North 10th Street, Suite 240 SouthArlington, Virginia 22201or call (703) 907-7559JEDEC Standard No. JESD84-C44-i-Embedded MultiMediaCard (eMMC) Mechanical Standar
10、d, with Optional Reset SignalForewordThe Embedded MultiMediaCard (eMMC) Mechanical Standard has been prepared by JEDEC. TheMultiMediaCard Association, hereafter referred to as MMCA, exists to promote adoption of a globalstandard for a compact, robust, affordable storage and retrieval device, the Mul
11、tiMediaCard. Consumersworldwide will benefit from this standard, allowing them to carry with them, information andentertainment that fits their needs, wherever they are, whenever they wish.JEDEC has taken the basic MMCA specification and adopted it for embedded applications, calling it “eMMC.” In ad
12、dition to the packaging differences, eMMC devices use a reduced voltage interface. These specifications are detailed in the JEDEC Standard for Embedded MultiMediaCard (eMMC)eMMC/Card Product Standard, JESD84-Axx.The purpose of the standard is the mechanical definition of the eMMC.IntroductionMultiMe
13、diaCards are universal data storage and communication media. It is designed to cover a wide areaof applications such as smart phones, cameras, organizers, PDAs, digital recorders, MP3 players, pagers,electronic toys, etc. Targeted features are high mobility and high performance at a low cost price.
14、Thesefeatures include low power consumption and high data throughput at the memory card interface.MultiMediaCard communication is based on an advanced 11-signal bus. The communication protocol isdefined as a part of this standard and referred to as the MultiMediaCard mode.JEDEC Standard No. JESD84-C
15、44 -ii-JEDEC Standard No. JESD84-C44Page 1Embedded MultiMediaCard (eMMC) Mechanical Standard, with Optional Reset Signal(From JEDEC Board Ballot JCB-09-26, formulated under the cognizance of the JC-64 Committee on Flash memory modules.)1 ScopeThis standard describes the mechanical features of the eM
16、MC.2 Normative referenceThere are no normative references for this document at this time.3 Terms and definitionsFor the purposes of this publication, the following terms and definitions apply:MMC: MultiMediaCardeMMC: Embedded MultiMediaCardJEDEC Standard No. JESD84-C44Page 24 eMMC General descriptio
17、nThe JEDEC eMMC Mechanical Standard describes the mechanical and physical attributes of the Embed-ded MultiMediaCard.There are four physical configurations, AA, AB, AC and BA, that are each discussed in this document.NOTE As used in this document, “shall” or “will” denotes a mandatory provision of t
18、he standard. “Should” denotesa provision that is recommended but not mandatory. “May” denotes a feature whose presence does not preclude com-pliance, that may or may not be present at the option of the implementor.4.1 Device signalsJEDEC eMMC devices transfer data via a configurable number of data-b
19、us signals. The communicationsignals are shown in Table 1. Device initialization uses only the CMD channel and is, therefore, compatible with all devices.4.2 eMMC ComponentsBall assignments for AA, AB and AC devices are depicted in Figure 1 on page 3. Ball assignments for BAdevices are shown in Figu
20、re 2 on page 4.Table 1 Communication signalsSignal Symbol DescriptionClock CLK Each cycle of the clock directs a transfer on the command line and on the data line(s). The frequency can vary between the minimum and the maximum clock frequency.Command CMD This signal is a bidirectional command channel
21、 used for device initialization and com-mand transfers. The CMD signal has two operating modes: open-drain for initialization, and push-pull for command transfer. Commands are sent from the MultiMediaCard bus master to the device, and responses are sent from the device to the host.DATA DAT7:0 These
22、are bidirectional data signals. The DAT signals operate in push-pull mode.By default, after power-up or RESET, only DAT0 is used for data transfer. The memory controller can configure a wider data bus for data transfer using either DAT3:0 (4-bit mode) or DAT7:0 (8-bit mode).JEDEC eMMC includes inter
23、nal pull-up resistors for data lines DAT7:1. Immediately after entering the 4-bit mode, the device disconnects the internal pull-up resistors on the DAT1, DAT2, and DAT3. Correspondingly, immediately after entering the 8-bit mode, the device disconnects the internal pull-ups on the DAT1DAT7.Reset RS
24、T_n Reset signal is used for host resetting device, moving the device to pre-idle state.By default, the RST_n signal is temporary disabled in device. Host need to set bit0:1 in the extended CSD register 162 to 0x1 to enable this functionality before the host uses.JEDEC Standard No. JESD84-C44Page 34
25、 eMMC General description (contd)Figure 1 Ball assignment: AA, AB and AC devices (see MO-276 for details)NOTE Some previous versions of the specifcation, either product specification or mechanical specification, had defined reserved ball as NC balls. The NC balls could have been connected to ground
26、in system board. But some of the NC balls could be assigned for new signals in the future. These balls are assigned as RFU in v4.4 mechanical specification. Any new implementations should use the new ball assignments and leave the RFU balls floating on system board.JEDEC Standard No. JESD84-C44Page
27、44 eMMC General description (contd)Figure 2 Ball assignments: BA devices (see MO-276 for details)NOTE Some previous versions of the specifcation, either product specification or mechanical specification, had defined reserved ball as NC balls. The NC balls could have been connected to ground in syste
28、m board. But some of the NC balls could be assigned for new signals in the future. These balls are assigned as RFU in v4.4 mechanical specification. Any new implementations should use the new ball assignments and leave the RFU balls floating on system board.4.3 eMMC Physical descriptionJEDEC eMMC ha
29、s 11 signals. The host is connected to the device using a dedicated 11-ball connector.Ball assignments are shown in Table 2 on page 5. Note that Table 2 continues on the following page.JEDEC Standard No. JESD84-C44Page 54 eMMC General description (contd)Table 2 Ball assignments169-Ball Devices 153-B
30、all Devices Symbol Type Ball FunctionAA, AB and AC DevicesBA DeviceW6 M6 CLK Input Clock: Each cycle directs a 1-bit transfer on the com-mand and DAT lines.W5 M5 CMD Input Command: A bidirectional channel used for device initial-ization and command transfers. Command has two operating modes:1) Open-
31、drain for initialization.2) Push-pull for fast command transfer.H3 A3 DAT0 I/O Data I/O0: Bidirectional channel used for data transfer.H4 A4 DAT1 I/O Data I/O1: Bidirectional channel used for data transfer.H5 A5 DAT2 I/O Data I/O2: Bidirectional channel used for data transfer.J2 B2 DAT3 I/O Data I/O
32、3: Bidirectional channel used for data transfer.J3 B3 DAT4 I/O Data I/O4: Bidirectional channel used for data transfer.J4 B4 DAT5 I/O Data I/O5: Bidirectional channel used for data transfer.J5 B5 DAT6 I/O Data I/O6: Bidirectional channel used for data transfer.J6 B6 DAT7 I/O Data I/O7: Bidirectional
33、 channel used for data transfer.U5 K5 RST_n Input Reset signal pinM6, N5, T10, U9 E6, F5, J10, K9 VCCSupply VCC: Flash memory I/F and Flash memory power supply.K6, W4, Y4, AA3, AA5C6, M4, N4, P3, P5 VCCQ Supply VCCQ: Memory controller core and MMC interface I/O power supply.M7, P5, R10, U8 E7, G5, H
34、10, K8 VSSSupply VSS: Flash memory I/F and Flash memory ground connection.K4, Y2, Y5, AA4, AA6C4, N2, N5, P4, P6 VSSQ Supply VSSQ: Memory controller core and MMC I/F ground connection.K2 C2 VDDiVDDi:Connect 0.1F capacitor from VDDi to ground.JEDEC Standard No. JESD84-C44Page 6MiscellaneousL4 D4 NC I
35、ndex Index: Can be connected to ground or left floating.A4, A6, A9, A11, B2, B13, D1, D14, H1, H2, H8, H9, H10, H11, H12, H13, H14, J1, J7, J8, J9, J10, J11, J12, J13, J14, K1, K3, K7, K8, K9, K10, K11, K12, K13, K14, L1, L2, L3, L12, L13, L14, M1, M2, M3, M12, M13, M14, N1, N2, N3, N12, N13, N14, P
36、1, P2, P12, P13, P14,R1, R2, R3, R12, R13, R14, T1, T2, T3, T12, T13, T14, U1, U2, U3, U12, U13, U14, V1, V2, V3, V12, V13, V14, W1, W2, W3, W7, W8, W9, W10, W11, W12, W13, W14, Y1, Y3, Y6, Y7, Y8, Y9, Y10, Y11, Y12, Y13, Y14, AA1, AA2, AA8, AA9, AA11, AA12, AA13, AA14, AE1, AE14, AG2, AG13, AH4, AH
37、6, AH9, AH11A1, A2, A8, A9, A10, A11, A12, A13, A14, B1, B7, B8, B9, B10, B11, B12, B13, B14, C1, C3, C7, C8, C9, C10, C11, C12, C13, C14, D1, D2, D3, D12, D13, D14, E1, E2, E3, E12, E13, E14, F1, F2, F3, F12, F13, F14, G1, G2, G12, G13, G14, H1, H2, H3, H12, H13, H14, J1, J2, J3, J12, J13, J14, K1,
38、 K2, K3, K12, K13, K14, L1, L2, L3, L12, L13, L14, M1, M2, M3, M7, M8, M9, M10, M11, M12, M13, M14, N1, N3, N6, N7, N8, N9, N10, N11, N12, N13, N14, P1, P2, P8, P9, P11, P12, P13, P14NC No connect:Can be connected to ground or left floating.H6, H7, K5, M5, M8, M9, M10, N10, P3, P10, R5, T5, U6, U7,
39、U10, AA7, AA10A6, A7, C5, E5, E8, E9, E10, F10, G3, G10, H5, J5, K6, K7, K10, P7, P10RFU Reserved for future use.Left it floating for future use.Table 2 Ball assignments (continued)169-Ball Devices 153-Ball Devices Symbol Type Ball FunctionAA, AB and AC DevicesBA DeviceP.O. Box 303, Sunol, CA 94586,
40、 U.S.A. www.mmca.orgMultiMediaCard, MMCA, and the MMCA logo are trademarks of the MultiMediaCard Association. All other trademarks are the property of their respective owners.Standard Improvement Form JEDEC: _JESD84-C44_ The purpose of this form is to provide the Technical Committees of JEDEC with i
41、nput from the industry regarding usage of the subject standard. Individuals or companies are invited to submit comments to JEDEC. All comments will be collected and dispersed to the appropriate committee(s).If you can provide input, please complete this form and return to:JEDECAttn: Publications Dep
42、artment2500 Wilson Blvd. Suite 220Arlington, VA 22201-3834Fax: 703.907.75831. I recommend changes to the following:Requirement, paragraph number:Test method number: Paragraph number:The referenced paragraph number has proven to be:Unclear Too rigid In errorOther:2. Recommendations for correction:3. Other suggestions for document improvement:Submitted by:Name: Phone:Company: Email:AddressCity/State/Zip Date:
