ia186em Innovasic Semiconductor Inc., ia186em Datasheet - Page 54

• Manufacturer Part Number: ia186em
• Description: 8-bit/16-bit Microcontrollers
• Manufacturer: Innovasic Semiconductor Inc.

IA186EM/IA188EM
8-Bit/16-Bit Microcontrollers
4.21
With the exception of word accesses to odd memory locations or between locked memory
addresses, DMA transfers have a higher priority than CPU transfers. Because the CPU cannot
access memory during a DMA transfer and a DMA transfer cannot be suspended by an interrupt
request, continuous DMA activity will increase interrupt delay. An NMI request halts any DMA
activity, however, enabling the CPU to respond promptly to the request.
4.22
The asynchronous serial port employs standard industry communication protocols in its
implementation of full duplex, bi-directional data transfers. The port can be either the source or
destination of DMA transfers.
The following features are supported:
x1, x2
The relative priority of one DMA channel with respect to the other (Bit [5])
Acceptance of DMA requests from Timer 2 (Bit [4])
Byte or Word transfers (Bit [0])
DMA Priority
Asynchronous Serial Port
Full-duplex data transfers
7-, 8-, or 9-bit data transfers
Odd, even, or no parity
One or two stop bits
PLL
®
Power-Save
(/2 to /128)
Divisor
Figure 10. DMA Unit
UNCONTROLLED WHEN PRINTED OR COPIED
Processor Internal Clock
Mux
Mux
Page 54 of 145
IA211050831-16
Drive enable
Time Delay
6 ±2.5nS
Drive enable
December 24, 2008
http://www.Innovasic.com
Customer Support:
Data Sheet
1-888-824-4184
clkouta
clkoutb