ATmega8HVA Atmel Corporation, ATmega8HVA Datasheet - Page 126

• Manufacturer Part Number: ATmega8HVA
• Manufacturer: Atmel Corporation

Specifications of ATmega8HVA

• Flash (kbytes): 8 Kbytes
• Pin Count: 28
• Max. Operating Frequency: 4 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 3
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 6
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 6
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1.9
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -20 to 85
• I/o Supply Class: 1.8 to 9.0
• Operating Voltage (vcc): 1.8 to 9.0
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

23.7
23.8
126
Charge High-current Protection
Battery Protection CPU Interface
ATmega8HVA/16HVA
When the Discharge High-current Protection is activated, the external D-FET and C-FET are dis-
abled and a Current Protection Timer is started. This timer ensures that the FETs are disabled
for at least one second. The application software must then set the DFE and CFE bits in the FET
Control and Status Register to re-enable normal operation. If the D-FET is re-enabled while the
loading of the battery still is too large, the Discharge High-current Protection will be activated
again.
If the voltage at the PI/NI pins is above the Charge High-current Detection level for a time longer
than High-current Protection Reaction Time, the chip activates Charge High-current Protection.
When the Charge High-current Protection is activated, the external D-FET and C-FET are dis-
abled and a Current Protection Timer is started. This timer ensures that the FETs are disabled
for at least one second. The application software must then set the DFE and CFE bits in the FET
Control and Status Register to re-enable normal operation. If the C-FET is re-enabled and the
charger continues to supply too high currents, the Charge High-current Protection will be acti-
vated again.
The Short-circuit, Over-current and High-current Protection parameters are programmable to
adapt to different types of batteries. The parameters are set by writing to I/O Registers. The
Parameter Registers can be locked after the initial configuration, prohibiting any further updates
until the next Hardware Reset.
Refer to ”Register Description for Battery Protection” on page 125 for register descriptions.
The Battery Protection CPU Interface is illustrated in Figure 22-1.
Figure 23-1. Battery Protection CPU Interface
Each protection has an Interrupt Flag. Each Flag can be read and cleared by the CPU, and each
flag has an individual interrupt enable. All enabled flags are combined into a single battery pro-
Battery Protection
Parameter Lock
Register
PI
NI
Battery Protection
Level Register
LOCK?
Battery Protection
Timing Register
Protection
Current
Battery
LOCK?
Battery Protection
Control Register
LOCK?
Power-off
Interrupt
Request
Protection
Current
8-BIT DATA BUS
Acknowledge
Protection
Interrupt
Register
Interrupt
10
Battery
Control
/
FET
5
5
/
/
8024A–AVR–04/08