7/30/2019
Cora Z7 Reference Manual [Reference.Digilentinc]
https://reference.digilentinc.com/reference/programmable-logic/cora-z7/reference-manual?_ga=2.21685883.1349070004.1564406803-1961480359.… 13/23
into a single device allows the Cora Z7 to be programmed, communicated with via UART, and powered from a computer attached with a
single Micro USB cable.
The DTR signal from the UART controller on the FT2232HQ is connected to MIO12 of the Zynq device via JP1. Should the Arduino IDE
be ported to work with the Cora Z7, this jumper can be shorted and MIO12 could be used to place the Cora Z7 in a “ready to receive a new
sketch” state. This would mimic the behavior of typical Arduino IDE boot-loaders.
The Cora Z7 provides a microSD slot (J10) for non-volatile external memory storage as well as for booting the Zynq. The slot is wired to
Bank 1/501 MIO[40-47], including the Card Detect signal. On the Zynq PS, peripheral SDIO 0 is mapped out to these pins and controls
communication with the SD card. The pinout can be seen in Table 6.1. The peripheral controller supports 1-bit and 4-bit SD transfer
modes, but does not support SPI mode. Based on the
Zynq Technical Reference manual
(http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf)
, SDIO host mode is the only mode supported.
Signal Name
Description
Zynq Pin
SD Slot Pin
SD_D0
Data[0]
MIO42
7
SD_D1
Data[1]
MIO43
8
SD_D2
Data[2]
MIO44
1
SD_D3
Data[3]
MIO45
2
SD_CCLK
Clock
MIO40
5
SD_CMD
Command
MIO41
3
SD_CD
Card Detect
MIO47
9
Table 6.1. microSD pinout
The SD slot is powered from the 3.3V rail, but is connected through MIO Bank 1/501 (1.8V). Therefore, a TI TXS02612 level shifter is
used to perform the necessary translation. The TXS02612 is actually a 2-port SDIO port expander, but only its level shifter function is used.
The connection diagram can be seen in Figure 6.1. Mapping out the correct pins and configuring the interface is handled by the Cora Z7
Zynq presets file, available through the Cora Z7 Resource Center
(https://reference.digilentinc.com/reference/programmable-logic/cora-z7/start)
Figure 6.1. microSD slot signals
Both low speed and high speed cards are supported, as the maximum clock frequency is 50 MHz (). A Class 4 card or better is
recommended.
Refer to section 3.1, microSD Boot Mode, for information on how to boot the Cora Z7 from an SD card. For more information, consult
the
Zynq Technical Reference manual
(http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf)
.
6 microSD Slot
