Clock Generation
15-15
Clock Generation and System Reset Management
Clock signals for each clock domain of the DSP subsystem are as follows:
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MPU-controlled:
J
DSP processor clock: DSP_CK, which is CK_GEN2 divided by 1, 2, 4,
or 8, as programmed via the DSPDIV bits of the MPU clock control
register (ARM_CKCTL). The enabling of DSP_CK while the DSP is in
the reset state is controlled by the EN_DSPCK bit of the MPU clock
control register (ARM_CKCTL).
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DSP MMU clock: DSPMMU_CK, as derived from CK_GEN2 divided
by 1, 2, 4, 8, as programmed by the DSPMMUDIV bits of the MPU
clock control register (ARM_CKCTL). Take care in selecting clocking
schemes so as to not exceed the maximum frequency of the DSP
MMU. See the OMAP5910 device datasheet for absolute timing
limits.
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DSP-controlled:
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DSP GPIO (DSP_GPIO_CK), as derived from CK_GEN2 divided by
1, 2, 4, 8 (as programmed by DSP_CKCTL GPIODIV) or CLKIN, as
selected by the GPIOXO bit of the DSP clock control register
(DSP_CKCTL). The clock is enabled by the EN_GPIOCLK bit of the
DSP idle mode entry 2 register (DSP_IDLECT2). The IDLE mode is
controlled by the IDLG–PIO_DSP bit of the DSP idle mode entry 1
register (DSP_IDLECT1).
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DSP public peripherals (McBSPs, MCSIs): DSPXOR_CK, which is
derived from CLKIN. The clock is enabled by the EN_XORPCK bit of
the DSP idle mode entry 2 register (DSP_IDLECT2). The IDLE mode
is controlled by the IDLXORP_DSP bit of the DSP idle mode entry 1
register (DSP_IDLECT1).
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DSP internal timers: DSPTIM_CK is selected from either CK_GEN2/2
or CLKIN via the DSP_TIMXO bit of the DSP clock control register
(DSP_CKCTL). The clock is enabled by the EN_TIMCLK bit of the
DSP idle mode entry 2 register (DSP_IDLECT2). The IDLE mode is
controlled by the IDLTIM_DSP bit of the DSP idle mode entry 1
register (DSP_IDLECT1).
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DSP watchdog timers (low frequency, derived from CLKIN divided by
14): DSPWD_CK. The clock is enabled by the EN_WDCLK bit of the
DSP idle mode entry 2 register (DSP_IDLECT2). The IDLE mode is
controlled by the IDLWDT_DSP bit of the DSP idle mode entry 1 regis-
ter (DSP_IDLECT1). The watchdog timer clock can only be disabled
or idled when not in watchdog mode.