ia186em Innovasic Semiconductor Inc., ia186em Datasheet - Page 46

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

IA186EM/IA188EM
8-Bit/16-Bit Microcontrollers
4.4
The operation of the CPU and peripherals operate at a slower clock frequency when in power
save mode, reducing power consumption and thermal dissipation. Should an interrupt occur, the
microcontroller returns to its normal operating frequency automatically on the internal clock’s
next rising edge in t
frequency during the power-save mode period.
4.5
The highest priority interrupt, res_n (Reset) must be held low for 1 mS during power-up to
initialize the microcontroller correctly. This operation makes the device cease all instruction
execution and local bus activity. The microcontroller begins instruction execution at physical
address FFFF0h when res_n becomes inactive and after an internal processing interval with
ucs_n is asserted and three wait states. Reset also sets up certain registers to predetermined
values and resets the Watchdog timer.
4.6
The data on the address/data bus (ad15–ad0 for the IA186EM, ao15–ao8 and ad7–ad0 for the
IA188EM) are written into the Reset Configuration register when reset is low. This data is
system dependent and is held in the Reset Configuration register after Reset is de-asserted. This
configuration data may be placed on the address/data bus by using weak external pull-up and
pull-down resistors or applied to the bus by an external driver, as the processor does not drive the
bus during reset. It is a method of supplying the software with some initial data after a reset; for
example, option jumper positions.
x1, x2
Power-Save Mode
Initialization and Reset
Reset Configuration Register
PLL
3
. Any clock-dependent devices should be reprogrammed for the change in
®
Power-Save
(/2 to /128)
Divisor
Figure 9. Organization of Clock
UNCONTROLLED WHEN PRINTED OR COPIED
Processor Internal Clock
Mux
Mux
Page 46 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