Part I: PCM-049/phyCORE-OMAP44xx System on Module
phyCORE-OMAP44xx
50
©
PHYTEC Messtechnik GmbH
2012
L-760e_1
1.8.1 Universal Asynchronous Interface
The phyCORE-OMAP44xx provides four high speed universal asynchronous interfaces with up to 3.6 Mbps.
Two of them (UART2 and UART 3) support hardware flow control (RTS and CTS signals).
The signals of UART1, UART2 and UART4 extend directly to the phyCORE-Connector providing signals at TTL
level.
UART3 of the OMAP44xx is connected to an RS-232 transceiver at U3. Thus it is possible to connect RS-232
compliant devices directly to the phyCORE-OMAP44xx. The configuration of the transceiver on the phyCORE-
OMAP44xx allows for error detection by having the inputs FORCEON and /FORCEOFF connected to the /INVALID
output. The transceiver is thus shut down when no valid receiver level is detected. For custom configurations
which do not require RS-232 level translation, the RS-232 transceiver at U3 can be removed and 0 Ohm resistor
network RN1 can be populated. In this configuration there is a direct short between the TTL level signal name
(e.g. UART3_RX) and RS-232 level signal name (e.g. X_UART3_RS232_RX), leaving the RS-232 level signal
names operating at TTL levels. The following table shows the location of the signals on the phyCORE-Connector.
Pin #
Signal
I/O
SL
Description
X1C10
X_UART1_TX
O
VCC_1V8_IO
Serial transmit signal UART1
X1D10
X_UART1_RX
I
1.8 V
Serial data receive signal UART 1
X1D11
X_UART3_RS232_TX
O
RS-232
Serial transmit signal UART 3
X1D12
X_UART3_RS232_RX
I
RS-232
Serial data receive signal UART 3
X1C12
X_UART3_RS232_CTS
I
RS-232
Serial clear to send UART 3
X1C13
X_UART3_RS232_RTS
O
RS-232
Serial request to send UART 3
X1D13
X_UART2_TX
O
VCC_1V8_IO
Serial transmit signal UART 2
X1D15
X_UART2_RX
I
1.8 V
Serial data receive signal UART 2
X1C14
X_UART2_CTS
I
1.8 V
Serial clear to send UART 2
X1C15
X_UART2_RTS
O
VCC_1V8_IO
Serial request to send UART 2
X1D16
X_UART4_TX
O
VCC_1V8_IO
Serial transmit signal UART 4
X1D17
X_UART4_RX
I
1.8 V
Serial data receive signal UART 4
Table 17:
Location of the UART Signals