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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 287
UG585 (v1.11) September 27, 2016
Chapter 9: DMA Controller
To avoid DMAC lock-up, the total MFIFO requirement of the set of channel programs must be equal
to or less than the maximum MFIFO depth. The DMAC maximum MFIFO depth is 1 words, 64 bits
each.
9.6 System Functions
9.6.1 Clocks
The controller is clocked by the CPU_1x clock for the APB interface and by the CPU_2x clock on the
AXI interface. Programming information for the CPU_1x and CPU_2x clocks is in Chapter 25, Clocks.
Example: Enable Clocks
1. Enable CPU_1x clock for APB. This clock is likely already enabled for the interconnect.
2. Enable CPU_2x clock for AXI. This clock is likely already enabled for the interconnect by writing
a 1 to slcr.AER_CLK_CTRL[DMA_CPU_2XCLKACT].
Peripheral Request Interface Clock
The peripheral request interface is clocked by the DMA{3:0}_ACLK signals. All of the interface signals are
listed in section 9.7.2 Peripheral Request Interface.
9.6.2 Resets
Controller Reset
The controller is reset using the slcr.DMAC_RST_CLTR[DMAC_RST] register bit. This bit is used in the
controller startup example shown in section Example: Start-up Controller.
PL Peripheral Reset
Use a general purpose I/O or other signal to the PL to reset PL peripherals.
9.6.3 Reset Configuration of Controller
Table 9-16 shows the tie-off signals used to program security state of the DMAC. Depending on the
state of the SLCR registers after reset, the DMA is configured in secure or non-secure mode. Refer to
the ARM PrimeCell DMA Controller (PL330) Technical Reference Manual: Security Usage for more
details.
Note: When set, each security state remains constant until the DMAC resets.
Note: After reset, the controller waits for software to begin executing, refer to section 9.2.3 DMA
Manager.