AM186ES Advanced Micro Devices, AM186ES Datasheet - Page 151

• Manufacturer Part Number: AM186ES
• Description: microcontrollers provide a low-cost/ high-performance solution for embedded system designers who wish to use the x86 architecture.
• Manufacturer: Advanced Micro Devices

10.2.1
Figure 10-3
Table 10-3
Serial Port 0/1 Control Registers
(SP0CT/SP1CT, Offset 80h/10h)
The serial port control registers control both the transmit and receive sections of the serial
port. The format of the serial port control registers is shown in Figure 10-3.
Serial Port Control Register
The value of SP0CT/SP1CT at reset is 0000h.
Bits 15–13: DMA Control Field (DMA)—This field configures the serial port for use with
DMA transfers according to the following table.
DMA Control Bits
DMA transfers to a serial port function as destination-synchronized DMA transfers. A new
transfer is requested when the transmit holding register is empty. This corresponds with
the assertion of the THRE bit in the serial port status register in non-DMA mode. When the
port is configured for DMA transmits, the corresponding transmit interrupt is disabled
regardless of the setting of the TXIE bit.
DMA transfers from the serial port function as source-synchronized DMA transfers. A new
transfer is requested when the serial port receive register contains valid data. This
corresponds with the assertion of the RDR bit in the serial port status register in non-DMA
mode. When the port is configured for DMA receives, the corresponding receive interrupt
is disabled regardless of the setting of the RXIE bit. Receive status interrupts may still be
taken, as configured by the RSIE bit.
Hardware handshaking may be used in conjunction with serial port DMA transfers.
DMA Bits
15
RSIE
TXIE
BRK
TB8
000b
001b
010b
011b
100b
101b
110b
111b
DMA
FC
Asynchronous Serial Port
Receive
Reserved
No DMA
No DMA
No DMA
DMA0
DMA1
DMA0
DMA1
7
Transmit
Reserved
No DMA
No DMA
No DMA
DMA1
DMA0
DMA0
DMA1
MODE
PE
EVN
RMODE
TMODE
RXIE
0
10-5