UART Environments
12-12
The functional clock is either a 12-MHz or a 48-MHz clock. You can select the
clock with the CONF_MOD_UART3_CLK_MODE_R bit (30) of the
MOD_CONF_CTRL_0 register (see Section 6.8, OMAP5910 Configuration
Registers) as follows:
-
CONF_MOD_UART3_CLK_MODE_R = 0: 12 MHz (default)
-
CONF_MOD_UART3_CLK_MODE_R = 1: 48 MHz
The NDMA_REQ [1:0] are connected to DMA request [19:18] of both the MPU
system DMA controller and the DSP DMA controller.
NDMA_REQ[1] is a RX request and the NDMA_REQ[0] is a TX request.
NIRQ from UART2 is connected to:
-
The interrupt line IRQ[15] of the MPU level 1 interrupt handler
-
The interrupt line IRQ[10] of the DSP level 1 interrupt handler
Figure 12–6 shows the UART3 environment.
Figure 12–6. UART3 Environment
MPU TIPB (public)
DSP TIPB (public)
Interrupt to MPU
Interrupt to DSP
OMAP5910
UART3
FCLK
IRDA_SELECT
NRESET
NIRQ
NDMAREQ
DMA request (1:0)
(rx:tx)
2
Input clock
TI peripheral bus
ULPD
Uart1_dpll_clk
12 MHz
48 MHz
1
0
TIPB switch
P_CLK
P_NBRST
CLKIN_DSP
CLKIN_MPU
NRESET
P_NIRQ
P_NDMAREQ
DSP PER_CLK (12 MHz)
MPU PER_CLK (12 MHz)
PER RESET
IRQ(15) _ L1
MPU interrupt level1
IRQ(10) – L1
DSP interrupte level1
DMA(19:18)
DSP DMA
DMA(19:18)
MPU system DMA
CTS3
RTS3
TX
RX
TXIR
RXIR
DTR3
DSR3
RX3
TX3
1
1
RTS
SD_MODE
(1:0)