UART Environments
12-8
12.2.2 UART2 Environment
UART2 is an UART modem with autobaud capability.
Table 12–3 lists the UART2 modem signals accessible at the OMAP5910
level.
Table 12–3. Available UART2 Signals
Generic UART Signal Name
Description
UART1 Signal Name
RX
Serial data input
RX2
TX
Serial data output
TX2
CTS
Clear to send input
CTS2
RTS
Request to send input
RTS2
FSR
Receive frame (input only)
Not available (internal feedback
from FSX)
BDCLK
16x baud clock input
BDCLK2
The functional clock is either a 32-kHz/12-MHz or a 48-MHz clock. You can
select the clock with the CONF_MOD_UART2_CLK_MODE_R bit (30) of the
MOD_CONF_CTRL_0 register (see Section 6.8, OMAP5910 Configuration
Registers) as follows:
-
CONF_MOD_UART1_CLK_MODE_R = 0: 32 kHz/12 MHz (default)
-
CONF_MOD_UART1_CLK_MODE_R = 1: 48 MHz
The frequency of the 32-kHz/12-MHz clock depends on the OMAP5910
system state:
-
32 kHz in deep sleep modes
-
12 MHz in big sleep and awake mode
Note that the UPLD clock control register (CLOCK_CTRL_REG) bit 0
MODEM_32K_EN must be controlled as follows:
-
MODEM_32K_EN = 0: Disables 32-kHz on UART clock in deep sleep
-
MODEM_32K_EN = 1: Enables 32-kHz on UART clock when in deep
sleep
The reset condition is 0.
When the CONF_MOD_UART1_CLK_MODE_R = 0 and MODEM_32K_ EN = 1,
the UART2 operates at 32kHz input clock while the device is in deep sleep.
