466130 Datasheet, PDF (34/36 Pages) ATMEL Corporation – 8-bit Microcontroller with 64/128K Bytes of ISP Flash

10. Datasheet Revision History for ATmega32U6/AT90USB64/128
Please note that the referring page numbers in this section are referred to this document. The
referring revision in this section are referring to the document revision.
10.1
Changes from 7593A to 7593B
1. Changed default configuration for fuse bytes and security byte.
2. Suppression of timer 4,5 registers which does not exist.
3. Updated typical application schematics in USB section
10.2 Changes from 7593B to 7593C
1. Update to package drawings, MQFP64 and TQFP64.
10.3
Changes from 7593C to 7593D
1. For further product compatibility, changed USB PLL possible prescaler configurations.
Only 8MHz and 16MHz crystal frequencies allows USB operation (See Table 6-11 on
page 49).
10.4
Changes from 7593D to 7593E
1. Updated PLL Prescaler table: configuration words are different between AT90USB64x
and AT90USB128x to enable the PLL with a 16 MHz source.
2. Cleaned up some bits from USB registers, and updated information about OTG timers,
remote wake-up, reset and connection timings.
3. Updated clock distribution tree diagram (USB prescaler source and configuration
register).
4. Cleaned up register summary.
5. Suppressed PCINT23:8 that do not exist from External Interrupts.
6. Updated Electrical Characteristics.
7. Added Typical Characteristics.
8. Update Errata section.
10.5
Changes from 7593E to 7593F
1. Removed ’Preliminary’ from document status.
2. Clarification in Stand by mode regarding USB.
10.6 Changes from 7593F to 7593G
1. Updated Errata section.
10.7
Changes from 7593G to 7593H
1. Added Signature information for 64K devices.
2. Fixed figure for typical bus powered application
3. Added min/max values for BOD levels
4. Added ATmega32U6 product
5. Update Errata section
6. Modified descriptions for HWUPE and WAKEUPE interrupts enable (these interrupts
should be enabled only to wake up the CPU core from power down mode).
34 ATmega32U6/AT90USB64/128
7593JS–AVR–03/09