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Preliminary User's Manual l TQMLS1028A UM 0001 l © 2019, TQ-Systems GmbH
Page 11
4.5
System Clock
The system clock is fixed at 100 MHz. Spread spectrum clocking is not possible.
4.6
Flash
Assembled on TQMLS1028A:
•
QSPI NOR Flash
•
eMMC NAND Flash, Configuration as SLC is possible (higher reliability, half capacity)
External removable storage device:
•
SD card (on MBLS1028A)
All above mentioned options, except NAND flash, are supported (external SD card on carrier board).
4.6.1
QSPI NOR Flash
•
QSPI flash with 1.8 V I/O voltage, 4 or 8 bidirectional data lines, separate read strobe.
•
Software support for STR and DTR.
•
64 to 512 MByte
4.6.2
eMMC / SD card
The LS1028A CPU provides two SDHC interfaces. One is for SD cards (with switchable I/O voltage), the other for eMMC (with fixed
I/O voltage).
LS1028A
eMMC 5.x
SDHC2_CLK
SDHC2_CMD
CLK
CMD
SDHC2_DATA[7:0]
DAT[7:0]
SDHC2_RESET_B
RST#
SDHC2_STROBE
DS
VCC
VCCQ
1.8 V 3.3 V
Illustration 8:
Block diagram eMMC interface
The eMMC is connected to SDHC2. The maximum transfer rate corresponds to the HS400 mode (eMMC from 5.0).
4.7
SDRAM
DDR4 SDRAM is used on the TQMLS1028A. Expansion stages with 1, 2, 4 or 8 GB are possible.