50 www.xilinx.com Virtex-4 FPGA Configuration User Guide
UG071 (v1.12) June 2, 2017
Chapter 2: Configuration Interfaces
Readback Abort Sequence Description
An ABORT is signaled during readback as follows:
1. The readback sequence begins normally.
2. The user pulls the RDWR_B pin Low while the device is selected (CS_B asserted Low).
3. BUSY goes High if CS_B remains asserted (Low).
4. The ABORT ends when CS_B is deasserted.
ABORTs during readback are not followed by a status word, because the RDWR_B signal
is set for write control (FPGA SelectMAP data pins are inputs).
ABORT Status Word
During the configuration ABORT sequence, the device drives a status word onto the
SelectMAP data pins. The key for that status word is given in Table 2-5.
Figure 2-19: Configuration Abort Sequence
DATA[0:7]
BUSY
CCLK
STAT U S
ABORT
ug071_028_091207
CS_B
RDWR_B
Figure 2-20: Readback Abort Sequence
DATA[0:7]
BUSY
CCLK
FPGA
ABORT
ug071_029_031104
CS_B
RDWR_B