Rainbow Electronics ATmega64C1 - Manual (Page 293)

293
7647A–AVR–02/08
ATmega32/64/M1/C1
the EESAVE Fuse which will take effect once it is programmed. The fuses are also latched on
Power-up in Normal mode.
24.4 Signature Bytes
All Atmel microcontrollers have a three-byte signature code which identifies the device. This
code can be read in both serial and parallel mode, also when the device is locked. The three
bytes reside in a separate address space.
24.4.1 Signature Bytes
For the ATmega32M1 the signature bytes are:
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x95 (indicates 32KB Flash memory).
3. 0x002: 0x84 (indicates ATmega32M1 device when 0x001 is 0x95).
For the ATmega32C1 the signature bytes are:
1. 0x000: 0x1E (indicates manufactured by Atmel).
2. 0x001: 0x95 (indicates 32KB Flash memory).
3. 0x002: 0x84 (indicates ATmega32C1 device when 0x001 is 0x95).
24.5 Calibration Byte
The ATmega32/64/M1/C1 has a byte calibration value for the internal RC Oscillator. This byte
resides in the high byte of address 0x000 in the signature address space. During reset, this byte
is automatically written into the OSCCAL Register to ensure correct frequency of the calibrated
RC Oscillator.
24.6 Parallel Programming Parameters, Pin Mapping, and Commands
This section describes how to parallel program and verify Flash Program memory, EEPROM
Data memory, Memory Lock bits, and Fuse bits in the ATmega32/64/M1/C1. Pulses are
assumed to be at least 250 ns unless otherwise noted.
24.6.1 Signal Names
In this section, some pins of the ATmega32/64/M1/C1 are referenced by signal names describ-
ing their functionality during parallel programming, see
Figure 24-1 and Table 24-8 . Pins not
described in the following table are referenced by pin names.
The XA1/XA0 pins determine the action executed when the XTAL1 pin is given a positive pulse.
The bit coding is shown in
Table 24-10 .
When pulsing WR or OE, the command loaded determines the action executed. The different
Commands are shown in
Table 24-11 .