Figure 3-24. Emmc Topography - Motorola APX 5000 Service Manual

3-38
Symbol Type
CLK Input
CMD I/O
DAT[7:0] I/O
RST_n Input
V Supply
CC
V Supply
CCQ
1
V Supply
SS
1
V Supply
SSQ
V
DDI
NC –
RFU –
Note: 1. V and V
SS SSQ
controller
RST_n
Registers
CMD
CLK
OCR
V
DDI
CID
NAND Flash
Clock: 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: This signal is a bidirectional command channel used for command and
response transfers. The CMD signal has two bus modes: open-drain mode and push-pull
mode (see Operating Modes). Commands are sent from the MMC host to the device, and
responses are sent from the device to the host.
Data I/O: These are bidirectional data signals. The DAT signals operate in push-pull
mode. By default, after power-on or assertion of the RST_n signal, only DAT0 is used for
data transfer. The MMC controller can configure a wider data bus for data transfer either
using DAT[3:0] (4-bit mode) or DAT[7:0] (8-bit mode). eMMC includes internal pull-up
resistors for data lines DAT[7:1]. Immediately after entering the 4-bit mode, the device
disconnects the internal pull-up resistors on the DAT[3:1] lines. Upon entering the 8-bit
mode, the device disconnects the internal pull-ups on the DAT[7:1] lines.
Reset: The RST_n signal is used by the host for resetting the device, moving the device
to the pre-idle state. By default, the RST_n signal is temporarily disabled in the device.
The host must set ECSD register byte 162, bits[1:0] to 0x1 to enable this functionality
before the host can use it.
V : NAND interface (I/F) I/O and NAND Flash power supply.
CC
V : eMMC controller core and eMMC I/F I/O power supply.
CCQ
V : NAND I/F I/O and NAND Flash ground connection.
SS
V : eMMC controller core and eMMC I/F ground connection.
SSQ
Internal voltage node: At least a 0.1μF capacitor is required to connect V
1μF capacitor is recommended. Do not tie to supply voltage or ground.
No connect: No internal connection is present.
Reserved for future use: No internal connection is present. Leave it floating externally.
are connected internally.

Figure 3-24. eMMC Topography

e·MMC
MMC
CSD RCA
ECSD DSR
* internally connected.
Description
Theory of Operation
V
CC
V
CCQ
DAT[7:0]
*
V
SS
*
V
SSQ
: Controller
to ground. A
DDI