AT83EB5114 Atmel Corporation, AT83EB5114 Datasheet - Page 25

• Manufacturer Part Number: AT83EB5114
• Manufacturer: Atmel Corporation

Specifications of AT83EB5114

• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 11
• Adc Channels: 6
• Adc Resolution (bits): 10
• Adc Speed (ksps): 50
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Operating Voltage (vcc): 3.0 to 3.6
• Timers: 4
• Mask Rom (kbytes): 4
• Watchdog: Yes

Mode 0 (13-bit Timer)
Figure 7. Timer/Counter x (x= 0 or 1) in Mode 0
Mode 1 (16-bit Timer)
Figure 8. Timer/Counter x (x = 0 or 1) in Mode 1
Mode 2 (8-bit Timer with Auto-
Reload)
4311C–8051–02/08
INTx#
INTx#
Tx
Tx
F
CkIdle
TMOD reg
GATEx
TMOD reg
GATEx
F
CkIdle
/ 6
/ 6
TMOD reg
C/Tx#
operation.
Timer 0 overflow (count rolls over from all 1s to all 0s) sets the TF0 flag and generates
an interrupt request.
It is important to stop the Timer/Counter before changing modes.
Mode 0 configures Timer 0 as a 13-bit Timer which is set up as an 8-bit Timer (TH0 reg-
ister) with a modulo-32 prescaler implemented with the lower five bits of the TL0 register
(see Figure 7). The upper three bits of the TL0 register are indeterminate and should be
ignored. Prescaler overflow increments the TH0 register.
Mode 1 configures Timer 0 as a 16-bit Timer with the TH0 and TL0 registers connected
in a cascade (see Figure 8). The selected input increments the TL0 register.
Mode 2 configures Timer 0 as an 8-bit Timer (TL0 register) that automatically reloads
from the TH0 register on overflow (see Figure 9). TL0 overflow sets the TF0 flag in the
TCON register and reloads TL0 with the contents of TH0, which is preset by the soft-
ware. When the interrupt request is serviced, the hardware clears TF0. The reload
leaves TH0 unchanged. The next reload value may be changed at any time by writing it
to the TH0 register.
0
1
TCON reg
TCON reg
TRx
TRx
TMOD reg
C/Tx#
0
1
(8 bits)
(8 bits)
THx
THx
(5 bits)
(8 bits)
TLx
TLx
Overflow
Overflow
TCON reg
TCON reg
TFx
TFx
Timer x
Interrupt
Request
Timer x
Interrupt
Request
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