P4080 Development System User’s Guide, Rev. 0
52
Freescale Semiconductor
Programming Model
7.1.11
LED Data Register (PX_LED)
The LED data register (PX_LED) can be used to directly control the monitoring LEDs (for software
message purposes, as an example). Direct control of the LEDs is possible only when PX_CSR[LED] is set
to 1.
7.1.12
VELA Control Register (PX_VCTL)
The VELA control register (PX_VCTL) may be used to start and control the configuration reset sequencer
as well as other configuration/test-related features.
Table 32. PX_DATA Field Descriptions
Bits
Name
Description
0–7
DATA
Contents of SRAM array as indexed by PX_ADDR
Offset 0x0E
Access: Read/Write
0
7
R
LED
W
Reset
All zeros
Figure 36. LED Data Register (PX_LED)
Table 33. PX_LED Field Descriptions
Bits
Name
Description
0–7
LED
Corresponding values for monitoring LEDs L0–L7.
0 Does not illuminate the LED
1 Illuminates the LED
Offset 0x10
Access: Read/Write
0
3
4
5
6
7
R
—
WDEN
—
PWROFF
GO
W
Reset
All zeros
Figure 37. VELA Control Register (PX_VCTL)
Table 34. PX_VCTL Field Descriptions
Bits
Name
Description
0–3
—
Reserved
4
WDEN
Watchdog enable
0 Watchdog disabled
1 Watchdog enabled. If not disabled with 2^29 clock cycles (> 5 minutes at 30-ns clock), the system is
reset.
Note:
This is not a highly secure watchdog; software can reset this bit at any time, disabling the
watchdog.