User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 754
UG585 (v1.11) September 27, 2016
Chapter 30: XADC Interface
Note: Reading from an empty Read Data FIFO causes an APB slave bus error.
One packet remains in the XADC when the Command FIFO is emptied. To retrieve the packet, write a
dummy command.
30.3.3 Command Format
Figure 30-4 shows the data format of the PS-XADC interface commands. The
f
irst 16 LSBs of the
XADCIF_CMD_FIFO contain the DRP register data. For both read and write operations, the address
bits, XADCIF_CMD_FIFO [25:16], hold the DRP target register address. The command bits,
XADCIF_CMD_FIFO [29:26], specify a read, write, or no operation (see Table 30-2).
DPR Address and DRP Data
The full list of XADC DRP registers and instructions on how to
conf
igure them can be found in the
UG480
, 7 Series FPGAs and Zynq-7000 All Programmable SoC XADC Dual 12-Bit 1 MSPS
Analog-to-Digital Converter User Guide.
30.3.4 Read Data Format
The XADC data is returned in the lower 16 bits of the devcfg.XADCIF_RDFIFO register read. The
interpretation of the DRP data can be found in the UG480 LogiCORE User Guide
.
X-Ref Target - Figure 30-4
Figure 30-4: PS-XADC Interface Command Register
Table 30-2: PS-XADC Interface DRP Command Format
CMD [3:0] Operation
0000No operation
0001DRP read
0010DRP Write
Others Not defined
UG585_c30_12_021913
X X CMD [3:0] DRP Address [9:0] DRP Data [15:0]
31 30 29 26 25 16 15 0
X-Ref Target - Figure 30-5
Figure 30-5: PS-XADC Interface Read Data Format
UG585_c30_13_021913
DRP Data [15:0]
31
0
16 15 0