AT43USB325E-AC Atmel, AT43USB325E-AC Datasheet - Page 42

• Manufacturer Part Number: AT43USB325E-AC
• Description: IC USB KEYBOARD CTRLR HUB 64LQFP
• Manufacturer: Atmel
• Series: AVR®r

Specifications of AT43USB325E-AC

• Applications: Keyboard Controller
• Core Processor: AVR
• Program Memory Type: SRAM (16 kB)
• Controller Series: AT43USB
• Ram Size: 512 x 8
• Interface: SPI, 3-Wire Serial
• Number Of I /o: 42
• Voltage - Supply: 4.4 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

6. Timer/Counters
6.1
Figure 6-1.
42
CS10
CS11
CS12
CK
T0
T1
Timer/Counter Prescaler
AT43USB325
Timer/Counter Prescaler
0
The AT43USB325 provides two general-purpose Timer/Counters - one 8-bit T/C and one 16-bit
T/C. The Timer/Counters have individual prescaling selection from the same 10-bit prescaling
timer. Both Timer/Counters can either be used as a timer with an internal clock time base or as a
counter with an external pin connection which triggers the counting.
The four different prescaled selections are: CK/8, CK/64, CK/256 and CK/1024 where CK is the
oscillator clock. For the two Timer/Counters, added selections as CK, external source and stop,
can be selected as clock sources.
Timer/Counter1 Clock Source
TCK1
10-bit T/C Prescaler
CS00
CS01
CS02
0
Timer/Counter0 Clock Source
TCK0
3355C–USB–4/05