Table of Contents
Advertisement
TS-5700 User's Manual
5. Serial Ports
The four PC compatible asynchronous serial ports (COM1 through COM4) provide a means to communicate
with external serial devices such as printers, modems, etc. Each is independently configured as a standard PC
COM port that is compatible with the National Semiconductor NS16C450. Alternatively, these ports can be
changed to the 16C550 mode with 16 byte FIFOs in both the receive and transmit UART channels. COM1
appears in the I/O space at 3F8h - 3FFh and uses IRQ4. COM2 is located at 2F8h - 2FFh and uses IRQ3.
COM3 appears in the I/O space at 3E8h-3EFh. COM4 appears in the I/O space at 2E8h-2EFh. COM3 and
COM4 have a non-standard method for configuring interrupts;
Configuration Register for details.
By changing an internal configuration register in the Elan520, the serial clock to the COM ports can be switched
to a 10 times rate (18.432 MHz). This feature allows baud rates higher than 115 Kbaud (such as 230K baud or
576K baud), as well as non-standard lower baud rates (such as 24 Kbaud).
information, COM1 & COM2 only
The COM1 and COM2 ports may also be configured to use a DMA channel, which may be useful when very
high baud rates are being used. Download the
5.1 Serial Port Configuration Registers
Because both serial ports are 100% PC compatible, software written for the PC that accesses serial ports
directly or through standard BIOS calls will work without modification on the TS-5700. The details of the COM
port internal registers are available in most PC documentation books or consult the
Download the
AMD Elan SC520 user's manual
5.2 Serial Port Hardware
The COM2 RS-232 port has 7 signals supported: RXD, TXD, RTS, CTS, DTR, DSR, and DCD. This port can
interface to almost any RS-232 device. The COM1 RS-232 serial port has 4 signals supported: RXD, TXD, RTS
and CTS. This is quite sufficient to interface with the vast majority of serial devices. The TS-5700 COM ports are
accessible on two 10-pin Headers labeled COM1 and COM2. Adaptor cables are available to convert these into
standard 9-pin Sub-D male connectors.
Technologic Systems
see section 5.6
AMD Elan SC520 user's manual
for further details.
7
http://embeddedARM.com/
COM3 and COM4 Interrupt
See Appendix F
for further
for further details.
TL16C550 data sheet.
5/2009
Advertisement
Table of Contents
