Clock Generation
15-18
Many of the following clocks are the same as the traffic controller clock
(TC_CK) in terms of their frequencies, but not their IDLE controls. Each of the
clocks has separate IDLE control logic.
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Traffic controller clock, TC_CK, is derived from CK_GEN3 divided by 1,
2, 4, or 8, as programmed via the TCDIV bits of the MPU clock control reg-
ister (ARM_CKCTL). The MPU interrupt handler uses the TC_CK clock,
as set by the ARM_INTHCK_SEL bit of the MPU clock control register
(ARM_CKCTL). The IDLE mode is controlled by the IDLIF_ARM bit of the
MPU idle mode entry 1 register (ARM_IDLECT1).
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Local bus and local bus MMU clock, LB_CK, is the same as TC_CK. The
IDLE mode is controlled by the IDLLB_ARM bit of the MPU idle mode entry
1 register (ARM_IDLECT1). The LB_CK is enabled by the EN_LBCK bit
of the MPU idle mode entry 2 register (ARM_IDLECT2).
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MPU port interface (MPUI) clock is dependent not only on the
IDLAPI_ARM bit of the MPU idle mode entry 1 register (ARM_IDLECT1),
but also on DSP_IDLE.
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The system DMA controller clock, DMA_CK, is the same as TC_CK. The
IDLE mode is controlled by the IDLIF_ARM bit of the MPU idle mode entry
1 register (ARM_IDLECT1), and the clock is enabled by the DMACK_REQ
bit of the MPU idle mode entry 2 register (ARM_IDLECT2).
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The MPU peripheral bridge clock, TIPB_CK, is the same as TC_CK. The
IDLE mode is controlled by the IDLIF_ARM bit of the MPU idle mode entry
1 register (ARM_IDLECT1).
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LCD controller clock, LCD_CK, is derived from CK_GEN3 divided by 1, 2,
4, or 8, as programmed via the LCDDIV bit of the MPU clock control regis-
ter (ARM_CKCTL). This clock is enabled by the EN_LCDCK bit of the
MPU idle mode entry 2 register (ARM_IDLECT2). The IDLE mode is con-
trolled by the IDLLCD_ARM bit of the MPU idle mode entry 1 register
(ARM_IDLECT1).