32-kHz Timer
7-48
7.5.2
32-kHz Timer Registers
Base address for 32-kHz timer: FFFB:9000
Table 7–36 lists the 32-kHz timer registers. Table 7–38 through Table 7–40
describe the individual registers.
Table 7–36. 32-kHz Timer Registers
Name
Description
R/W
Size
Address
Offset
CR
Timer control
R/W
32 bits
FFFB:9000
0x08
TVR
Tick value
R/W
32 bits
FFFB:9000
0x00
TCR
Tick counter
R
32 bits
FFFB:9000
0x04
7.5.2.1
Synchronization Issues
Synchronization of reads and writes to the 32-kHz clock is done in different
ways for each register. This leads to slight restrictions concerning register
access (see Table 7–37).
Table 7–37. Read/Write Synchronization
Register Name
Read
Write
CR
Can be read anytime. The value read
is the last value written.
Two consecutive writes must be separated
by at least 1 CLK32 period (31
µ
s). If this is
not the case, the value written is not
guaranteed
TCR
Reads are resynchronized on
MPUXOR_CK clock to prevent
peripheral bus from timing out. Can
be read anytime, providing
MPUXOR_CK is running. If not, the
value is not guaranteed. Software
must wait one 32-kHz period after
turning on the MPUXOR_CK clock
before the TCR register can be read.
Writing to this has no effect.
TVR
Can be read anytime. The value read
is the last value written
Two consecutive writes must be separated
by at least 1 CLK32 period (31
µ
s). If this is
not the case the value written is not
guaranteed