Table 32: HS400 Capacitance and Resistors

Parameter

Symbol

Min.

Type

Max.

Unit

Remark

Pull-up resistance for CMD

RCMD

4.7

100

kOhm

Pull-up resistance for DAT0-7

RDAT

10

100

kOhm

Pull-down resistance for Data

Strobe

RDS

10

100

kOhm

Internal pull up resistance DAT1-

DAT7

Rint

10

150

kOhm

Single Device capacitance

CDevice

6

pF

9. eMMC Registers

Within the Device interface six registers are defined: OCR, CID, CSD, EXT_CSD, RCA and DSR. These can be accessed

only by corresponding commands (see Section 6.10 of JESD84-B51).

Table 33: eMMC Registers

Name

Width

(Bytes)

Description

Implementation

CID

16

Device Identification number, an individual number for identification.

Mandatory

RCA

2

Relative Device Address is the Device system address, dynamically

assigned by the host during initialization.

Mandatory

DSR

2

Driver Stage Register, to configure the Device’s output drivers.

Optional, not

implemented

CSD

16

Device Specific Data, information about the Device operation conditions.

Mandatory

OCR

4

Operation Conditions Register. Used by a special broadcast command to

identify the voltage type of the Device.

Mandatory

EXT_CSD

512

Extended Device Specific Data. Contains information about the Device

capabilities and selected modes. Introduced in standard v4.0

Mandatory

The host may reset the device by:



Switching the power supply off and back on. The device shall have its own power-on detection

circuitry which puts the device into a defined state after the power-on Device.



A reset signal



By sending a special command

9.1 OCR Register

The 32-bit operation conditions register (OCR) stores the VDD voltage profile of the Device and the access mode

indication. In addition, this register includes a status information bit. This status bit is set if the Device power

up procedure has been finished. The OCR register shall be implemented by all Devices.

Table 34: OCR register

OCR bit

VCCQ voltage window

typ. value

[6:0]

Reserved

000 0000b

[7]

1.70 – 1.95V

1b

[14:8]

2.0 – 2.6V

000 0000b

[23:15]

2.7 – 3.6V

1 1111 1111b

[28:24]

Reserved

0 0000b

[30:29]

Access Mode

10b (sector mode, for devices >2GB)

[31]

Card power up status bit (0=busy; 1=ready)1

Note 1: This bit is set to LOW if the Device has not finished the power up routine.

Confidential

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Rev.1.0 July 2023

32GB/64GB/128GB eMMC