Rainbow Electronics ATmega8HVD - Manual (Page 131)

131
8052B–AVR–09/08
ATmega4HVD/8HVD
24.4 Calibration Bytes
The ATmega4HVD/8HVD has a calibration byte for the Fast RC Oscillator. This byte resides in
a high byte in the signature address space. During Reset, the calibration byte for the Fast RC
Oscillator is automatically written into the corresponding calibration register.
24.5 Page Size
24.6 Serial Downloading
Both the Flash and EEPROM memory arrays can be programmed using the serial SPI bus
while RESET is pulled to GND. The serial interface consists of pins SCK, MOSI (input) and
MISO (output). After RESET is set low, the Programming Enable instruction needs to be exe-
cuted first before program/erase operations can be executed. NOTE, in
Table 24-8 on page
132 , the pin mapping for SPI programming is listed. Not all parts use the SPI pins dedicated
for the internal SPI interface.
Figure 24-1. Serial Programming and Verify
Table 24-6. No. of Words in a Page and No. of Pages in the Flash
Device Flash Size Page Size PCWORD No. of Pages PCPAGE PCMSB
ATmega4HVD 2K words (4K bytes) 32 words PC[4:0] 64 PC[10:5] 10
ATmega8HVD 4K words (8K bytes) 32 words PC[4:0] 128 PC[11:5] 11
Table 24-7. No. of Words in a Page and No. of Pages in the EEPROM
Device EEPROM Size Page Size PCWORD No. of Pages PCPAGE EEAMSB
ATmega4HVD 256 bytes 4 bytes EEA[1:0] 64 EEA[7:2] 7
ATmega8HVD 256 bytes 4 bytes EEA[1:0] 64 EEA[8:2] 8
VFET
BATT
GND
SCK
MISO
MOSI
RESET
3.0 - 6.0V