COP8AME9_14 Datasheet, PDF (40/102 Pages) Texas Instruments – COP8AME9 8-Bit CMOS Flash Microcontroller with 8k Memory, Dual Op Amps, Virtual EEPROM, Temperature Sensor, 10-Bit A/D and Brownout Reset

COP8AME9, COP8ANE9
SNOS930F – MARCH 2001 – REVISED MARCH 2013
www.ti.com
Timer T2 Clocking Scheme
Table 19 shows the relationship between the T2 clock, the Processor clock, and the T0 clock. Note that the T2
clock is always equal to the processor clock frequency when enabled.
Device Clock Mode
High Speed
Dual Clock
Low Speed
Table 19. Timer T2 Clocking Scheme
Idle Mode
0
1
0
1
0
1
T0 Clock
HS Clock
HS Clock
LS Clock
LS Clock
LS Clock
LS Clock
Procesor Clock
HS Clock
Off
HS Clock
Off
LS Clock
Off
T2 Clock if
T2IDLE = 1
HS Clock
HS Clock
HS Clock
HS Clock
LS Clock
LS Clock
T2 Clock if
T2IDLE = 0
HS Clock
Off
HS Clock
Off
LS Clock
Off
Power Saving Features
Today, the proliferation of battery-operated applications has placed new demands on designers to drive power
consumption down. Battery operated systems are not the only type of applications demanding low power. The
power budget constraints are also imposed on those consumer/industrial applications where well regulated and
expensive power supply costs cannot be tolerated. Such applications rely on low cost and low power supply
voltage derived directly from the “mains” by using voltage rectifier and passive components. Low power is
demanded even in automotive applications, due to increased vehicle electronics content. This is required to ease
the burden from the car battery. Low power 8-bit microcontrollers supply the smarts to control battery-operated,
consumer/industrial, and automotive applications.
The device offers system designers a variety of low-power consumption features that enable them to meet the
demanding requirements of today's increasing range of low-power applications. These features include low
voltage operation, low current drain, and power saving features such as HALT, IDLE, and Multi-Input Wake-Up
(MIWU).
This device supports three operating modes, each of which have two power save modes of operation. The three
operating modes are: High Speed, Dual Clock, and Low Speed. Within each operating mode, the two power save
modes are: HALT and IDLE. In the HALT mode of operation, all microcontroller activities are stopped and power
consumption is reduced to a very low level. In this device, the HALT mode is enabled and disabled by a bit in the
Option register. The IDLE mode is similar to the HALT mode, except that certain sections of the device continue
to operate, such as: the on-board oscillator, the IDLE Timer (Timer T0), and the Clock Monitor. This allows real
time to be maintained. During power save modes of operation, all on board RAM, registers, I/O states and timers
(with the exception of T0) are unaltered.
Two oscillators are used to support the three different operating modes. The high speed oscillator refers to the
oscillator connected to CKI and the low speed oscillator refers to the 32 kHz oscillator connected to pins L0 & L1.
When using L0 and L1 for the low speed oscillator, the user must ensure that the L0 and L1 pins are configured
for hi-Z input, L1 is not using CKX on the USART, and Multi-Input Wake-up for these pins is disabled.
A diagram of the three modes is shown in Figure 20.
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