Frame Adjustment Counter
7-199
MPU Public Peripherals
Figure 7–71. FAC Top-Level Diagram
USB function
MPU interrupt handler level 2
Irq0
ULPD
DS_WAKE_REQ_ON
ULPD_nIrq
Irq24
WKUP_REQ
12 MHz
CLKIN
PERCLK
Clock generation and management
OMAP5910
MPU_PER_RST
Gating
Reset
Reset
FAC_IRQ
PCLK
FAC
Registers
FARC
FSC
CTRL
STATUS
SYNC
Start
Frame
Frame
McBSP2
FSX
IRQ_ISO_ON
Start
counter
SYNC
counter
7.16.2 Synchronization and Counter Control
Because frame-start and frame-synchronization signals are from different
time domains, the FAC module synchronizes these two signals to the system
clock domain and uses the synchronized signals as the count enables. The
actual counters for frame synchronization and frame start are clocked by the
system clock.
The synchronization mechanism is based on the assumption that the system
clock is running at least eight times faster than frame synchronization and
frame start. Figure 7–72 and Figure 7–73 show the synchronization logic and
the counter hookup.