This section describes the features supplied by the eMMC/SD/SDIO controllers.
Compliance with standards:
- Full compliance with MMC/eMMC command/response sets as defined in the JC64 MMC/eMMC standard specification, v4.5.
- Full compliance with SD command/response sets as defined in the SD Physical Layer specification v3.01
- Full compliance with SDIO command/response sets and interrupt/read-wait suspend-resume operations as defined in the SD part E1 specification v3.00
- Full compliance with SD Host Controller Standard Specification sets as defined in the SD card specification Part A2 v3.00
Main features of the eMMC/SD/SDIO host controllers:
- Flexible architecture allowing support for new command structure
- 32-bit wide access bus to maximize bus throughput
- Designed for low power
- Programmable clock generation
- Dedicated DLL to support SDR104 mode (MMC1 only)
- Dedicated DLL to support HS200 mode (MMC2 only)
- Card insertion/removal detection and write protect detection
- L4 slave interface supports:
- 32-bit data bus width
- 8/16/32 bit access supported
- 9-bit address bus width
- Streaming burst supported only with burst length up to 7
- WNP supported
- L3 initiator interface Supports:
- 32-bit data bus width
- 8/16/32 bit access supported
- 32-bit address bus width
- Burst supported
- Built-in 1024-byte buffer for read or write
- Two DMA channels, one interrupt line
- Support JC 64 v4.4.1 boot mode operations
- Support SDA 3.00 Part A2 programming model
- Support SDA 3.00 Part A2 DMA feature (ADMA2)
- Supported data transfer rates:
- MMCi supports the following SD v3.0 data transfer rates:
- DS mode (3.3V IOs): up to 12 MBps (24 MHz clock)
- HS mode (3.3V IOs): up to 24 MBps (48 MHz clock)
- SDR12 (1.8V IOs): up to 12 MBps (24 MHz clock)
- SDR25 (1.8V IOs): up to 24 MBps (48 MHz clock)
- SDR50 (1.8V IOs): up to 48 MBps (96 MHz clock) - MMC1 and MMC3 only
- DDR50 (1.8V IOs): up to 48 MBps (48 MHz clock) - MMC1 only
- SDR104 (1.8V IOs) cards can be supported up to 192 MHz clock (96 MBps max) - MMC1 only
- MMCi supports the Default SD mode 1-bit data transfer up to 24Mbps (3MBps)
- Only MMC2 supports also the following JC64 v4.5 data transfer rates:
- Up to 192 MBps in eMMC mode, 8-bit SDR mode (192 MHz clock frequency)
- Up to 96 MBps in eMMC mode, 8-bit DDR mode (48 MHz clock frequency)
- All eMMC/SD/SDIO controllers are connected to 1,8V/3.3V compatible I/Os to support 1,8V/3.3V signaling
Note: eMMC functionality is supported fully by MMC2 only. The other MMC modules are capable of eMMC functionality, but are not timing-optimized for eMMC. For more information about timing limitations, see the data manual of the device.
The differences between the eMMC/SD/SDIO host controllers and a standard SD host controller defined by the SD Card Specification, Part A2, SD Host Controller Standard Specification, v3.00 are:
- The clock divider in the eMMC/SD/SDIO host controller supports a wider range of frequency than specified in the SD Memory Card Specifications, v3.0. The eMMC/SD/SDIO host controller supports odd and even clock ratio.
- The eMMC/SD/SDIO host controller supports configurable busy time-out.
- ADMA2 64-bit mode is not supported.
- There is no external LED control.
Note: Only even ratios are supported in DDR mode.
Table 27-1 lists the features supported in the 4.5 standard.
Table 27-1 Standard 4.5 Supported FeaturesFeature | Support | Limitation | Comment |
---|
Bus width | 1-bit mode | | x 1, 4, 8 bits |
| 4-bit mode | | |
| 8-bit mode | | |
Support density | No hardware limitation for density support | Limitation can come from file system (32 GiB). | |
Simple boot (CMD, alternate boot) | Yes | | Device ROM code supports the following boot modes:
- Alternate Boot
- Raw (UDA) Boot
- File System
|
| | | For more information about boot modes, see Memory Booting. in
Initialization. |
Sleep mode | Yes | | |
Reliable write | Yes | | |
Secure write protection | Yes | | |
Hardware reset | No | | Use the reset command if hardware reset is needed. |
Secure memory block (RPMB) | Yes | | |
Partition feature | Yes | | |
Secure erase | Yes | | |
DDR interface (bandwidth) | Up to 96 MBps in DDR mode – 8-bit | | |
High-priority interrupt (read while write) | Yes | | |
Background operation | Yes | | |
Enhanced reliable write | Yes | | |
HS200 mode | Yes | | |
Table 27-2 shows the supported by each MMCi host controller transfer rates and functionalities (SD, eMMC and SDIO).
Table 27-2 MMCi Supported Transfer Rates and Functionalities | SD(1) | eMMC | SDIO |
---|
MMC1 | Yes (Up to SDR104 mode) | Yes (Up to High Speed DDR mode; timings optimized for SD) | Yes (timings optimized for SD) |
MMC2 | Yes (Up to SDR25 mode; timings optimized for eMMC) | Yes (Up to HS200 mode) | Yes (timings optimized for eMMC) |
MMC3 | Yes (Up to SDR50 mode) | Yes (Up to High Speed SDR mode; timings optimized for SD/SDIO) | Yes (Up to SDR50 mode) |
MMC4 | Yes (Up to SDR25 mode) | Yes (Up to High Speed SDR mode; timings optimized for SD/SDIO) | Yes (Up to SDR25 mode) |
(1) 3.3V IO required for initial SD Card communication.