Datasheet

228
7728G–AVR–06/10
ATtiny87/ATtiny167
21.4 Calibration Byte
The ATtiny87/167 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.
21.5 Page Size
21.6 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 ATtiny87/167. Pulses are assumed to
be at least 250 ns unless otherwise noted.
21.6.1 Signal Names
In this section, some pins of the ATtiny87/167 are referenced by signal names describing their
functionality during parallel programming, see Figure 21-1 and Figure 21-9. 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 Figure 21-11.
When pulsing WR
or OE, the command loaded determines the action executed. The different
commands are shown in Figure 21-12.
Table 21-7. Number of Words in a Page and No. of Pages in the Flash
Device Flash Size Page Size PCWORD No. of Pages PCPAGE PCMSB
ATtiny87 4K words 64 words PC[5:0] 64 PC[11:6] 11
ATtiny167 8K words 64 words PC[5:0] 128 PC[12:6] 12
Table 21-8. Number of Words in a Page and No. of Pages in the EEPROM
Device EEPROM Size Page Size PCWORD No. of Pages PCPAGE EEAMSB
ATti ny87
ATti ny16 7
512 bytes 4 bytes EEA[1:0] 128 EEA[8:2] 8