UART Environments
12-10
There is an alternate wakeup from deep sleep: By programming bit 4 of the
UART2 SCR register, it is possible to create an interrupt by a low going edge
on RX or CTS. The interrupt would be generated by RX at time #2 in
Figure 12–4.
NDMA_REQ [1:0] are connected to the DMA request [15:14] of both 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 following:
-
Interrupt line IRQ[15] of the MPU level 2 interrupt handler
-
Interrupt line IRQ[4] of the DSP level 2 interrupt handler
Figure 12–5 shows the UART2 environment.
Figure 12–5. UART2 Environment
MPU TIPB (public)
DSP TIPB (public)
Interrupt to MPU
Interrupt to DSP
OMAP5910
TX2
UART2
FCLK
NRESET
NIRQ
NDMAREQ(1:0)
RX2
CTS2
RTS2
DMA request (1:0)
(rx:tx)
2
Input clock
TI peripheral bus
ULPD
Uart1_dpll_clk
Uart_mcko
32 kHz/12 MHz
48 MHz
1
0
TIPB switch
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)
MPU interrupt level2
IRQ(4)
DSP interrupt level2
DMA(15:14)
DSP DMA
DMA(15:14)
MPU system DMA
BDCLK2
UART2 Activity
detection
Periph_clk_nreq
chip_nwakeup