User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 759
UG585 (v1.11) September 27, 2016
Chapter 30: XADC Interface
30.5 Programming Guide for the DRP Interface
The XADC can also be accessed by instantiating a LogiCORE AXI XADC bridge in the PL. This method
provides more powerful features and easy access to all XADC registers and signals using a register
read/write programming model for microprocessors.
30.6 Programming Guide for the PL-JTAG Interface
The PS-XADC interface commands are similar to the JTAG DRP commands. Refer to the JTAG DRP
commands shown in UG480
, 7 Series FPGAs and Zynq-7000 All Programmable SoC XADC Dual 12-Bit
1 MSPS Analog-to-Digital Converter User Guide.
Note: PL-JTAG cannot access the XADC if the PS-XADC interface is accessing the XADC (i.e.,
devcfg.XADCIF_CFG [ENABLE] = 1).
30.7 System Functions
30.7.1 Clocks
Clocking is determined by the interface choice.
PS-XADC Interface Clocks
1. The PS-XADC interface uses FIFOs to cross between the PS system clock and the XADCIF clock.
2. PS system interface clock is the CPU_1x clock.
3. The XADCIF clock frequency is the PCAP_2x clock / [TCLKRATE].
a. The XADCIF clock maximum frequency is 50 MHz.
b. The PCAP_2x clock frequency is nominally 200 MHz.
c. The [TCLKRATE] bit: divide 2, 4 (default), 8, or 16.
See Chapter 25, Clocks for more information about the PS clocks.
Command and
Read Data FIFOs
devcfg.XADCIF_CMDFIFO XADC Interface Command FIFO Write
devcfg.XADCIF_RDFIFO XADC Interface Read Data FIFO Read
Table 30-3: Register Overview (Contd)
Function Mnemonic Description Type