Programmers Model
ARM DUI 0447J
Copyright © 2009-2014, ARM. All rights reserved.
4-13
ID052914
Non-Confidential
Table 4-8
shows the Flag registers.
The board provides the following distinct types of flag register:
•
The SYS_FLAGS Register is cleared by a normal reset, such as a reset caused by pressing
the reset button.
•
The SYS_NVFLAGS Register retains its contents after a normal reset and is only cleared
by a
Power-On Reset
(POR).
Flag and Nonvolatile Flag Registers
The SYS_FLAGS and SYS_NVFLAGS registers contain the current state of the flags.
Flag and Nonvolatile Flag Set Registers
The SYS_FLAGSSET and SYS_NVFLAGSSET registers set bits in the SYS_FLAGS and
SYS_NVFLAGS registers:
•
Write 1 to SET the associated flag.
•
Write 0 to leave the associated flag unchanged.
Flag and Nonvolatile Flag Clear Registers
Use the SYS_FLAGSCLR and SYS_NVFLAGSCLR registers to clear bits in the SYS_FLAGS
and SYS_NVFLAGS registers:
•
Write 1 to CLEAR the associated flag.
•
Write 0 to leave the associated flag unchanged.
4.4.6
MCI Register
The SYS_MCI Register characteristics are:
Purpose
Provides status information on the MultiMedia card socket
Usage constraints
There are no usage constraints.
Configurations
Available in all configurations.
Attributes
See
Table 4-3 on page 4-8
.
Figure 4-6 on page 4-14
shows the bit assignments.
Table 4-8 Flag registers
Register
Address offset
Access
Reset by
Description
SYS_FLAGS
0x0030
Read
Reset
Flag register
SYS_FLAGSSET
0x0030
Write
Reset
Flag Set register
SYS_FLAGSCLR
0x0034
Write
Reset
Flag Clear register
SYS_NVFLAGS
0x0038
Read
POR
Nonvolatile Flag register
SYS_NVFLAGSSET
0x0038
Write
POR
Nonvolatile Flag Set register
SYS_NVFLAGSCLR
0x003C
Write
POR
Nonvolatile Flag Clear register