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LS1028A
SDHC1_CLK
SDHC1_CMD
SDHC1_DAT[3:0]
S D CARD
OVDD
(1.8V)
EVDD
(3.3V/1.8V)
SDHC2_CLK
SDHC2_CMD
SDHC2_DAT[7:0]
eMMC-8GB
MTFC8GAKAJCN-
1M WT
SDHC2_DS
3V3
1V8
3V3
SDHC_VSEL
EVDD
S WITCH
1V8
3V3
EVDD
PULL-UPS
TO E VDD
PULL-UPS
TO 1V8
Figure 20. eSDHC architecture
The LS1028ARDB eSDHC1 interface is connected to a secure digital (SD) connector (P2) on board to support an SD card. For
default- or high-speed of SD card, the eSDHC1 controller and the SD card operate at EVDD (3.3 V) power. However, in case the
eSDHC1 controller requires the ultra-high speed (UHS) of the SD card, the card and the controller operates at 1.8 V. The EVDD
switch (FPF1321UCX) changes the 3.3 V supply to 1.8 V for the controller depending upon the value of SDHC_VSEL signal.
The following table describes EVDD switch output voltage depending upon the SD card speed and SDHC_VSEL value.
Table 19. EVDD switch output voltage
SD card speed
SDHC_VSEL
EVDD switch voltage
Default or high speed
0
3.3 V
Ultra-high speed (UHS)
1
1.8 V
To move from UHS state to default- or high-speed state of SD card, a power reset is required.
NOTE
I2C2 must be programmed in the RCW to serve as the card detect (CD_B) and write protect (WP) pins for the eSDHC1 interface.
This happens automatically when the SD card slot is selected as the boot device.
The LS1028ARDB eSDHC2 interface is connected to an 8 GB eMMC device, MTFC8GAKAJCN (from Micron) on the board. The
eMMC memory can support x1, x4 and x8 data width and data rate of HS400 mode. The eSDHC2 controller and the on-board
embedded eMMC memory operate at 1.8 V IO.
2.17 Mikro-click modules
The LS1028ARDB board provides two mikroBUS
™
connectors, mikroBUS1 (J29 and J30) and mikroBUS2 (J31 and J32). These
mikroBUS connectors support different types of mikro-click modules that can be accessed through SPI3, UART2, PWM, or I2C
interface. Since SPI and UART buses to the mikroBUS sockets are shared, modules using the same communication interface
(both SPI or both UART) cannot be used. However, a combination can be supported. For example, a UART based module and
Mikro-click modules
QorIQ LS1028A Reference Design Board Reference Manual, Rev. b, 11/2018
NXP Semiconductors
COMPANY CONFIDENTIAL
41
Содержание QorIQ LS1028A
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