AT89C5132 Atmel Corporation, AT89C5132 Datasheet - Page 50

• Manufacturer Part Number: AT89C5132
• Manufacturer: Atmel Corporation

Specifications of AT89C5132

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-12C
• Max I/o Pins: 44
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Uart: 1
• Adc Channels: 2
• Adc Resolution (bits): 10
• Adc Speed (ksps): 22.7
• Sram (kbytes): 2.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 2
• Isp: UART/USB
• Watchdog: Yes

Figure 12-1. Timer 0 and Timer 1 Clock Controller and Symbols
12.3
12.3.1
Figure 12-2. Timer/Counter x (x = 0 or 1) in Mode 0
50
Timer 0
AT89C5132
Mode 0 (13-bit Timer)
CLOCK
INTx
CLOCK
CLOCK
TIMx
OSC
Tx
PER
TMOD Reg
Timer 0 Clock Symbol
GATEx
CLOCK
÷ 6
TIM0
÷
2
Timer 0 functions as either a Timer or event Counter in four modes of operation. Figure 12-2
through Figure 12-8 show the logical configuration of each mode.
Timer 0 is controlled by the four lower Bits of TMOD register (see Table 41) and Bits 0, 1, 4 and
5 of TCON register (see Table 40). TMOD register selects the method of Timer gating (GATE0),
Timer or Counter operation (C/T0#) and mode of operation (M10 and M00). TCON register pro-
vides Timer 0 control functions: overflow flag (TF0), run control bit (TR0), interrupt flag (IE0) and
interrupt type control bit (IT0).
For normal Timer operation (GATE0 = 0), setting TR0 allows TL0 to be incremented by the
selected input. Setting GATE0 and TR0 allows external pin INT0 to control Timer operation.
Timer 0 overflow (count rolls over from all 1s to all 0s) sets TF0 flag generating an interrupt
request.
It is important to stop Timer/Counter before changing mode.
Mode 0 configures Timer 0 as a 13-bit Timer which is set up as an 8-bit Timer (TH0 register) with
a modulo 32 prescaler implemented with the lower five Bits of TL0 register (see Figure 12-2).
The upper three Bits of TL0 register are indeterminate and should be ignored. Prescaler over-
flow increments TH0 register. Figure 12-3 gives the overflow period calculation formula.
Figure 12-3. Mode 0 Overflow Period Formula
TMOD Reg
C/Tx#
CKCON.1
TCON Reg
T0X2
0
1
0
1
TRx
Timer 0 Clock
TFx
PER
(5 Bits)
TLx
=
CLOCK
CLOCK
OSC
PER
6
⋅
(16384 – (THx, TLx))
Timer 1 Clock Symbol
F
(8 Bits)
TIMx
THx
CLOCK
TIM1
÷
2
Overflow
CKCON.2
T1X2
0
1
TCON Reg
TFx
Timer 1 Clock
Timer x
Interrupt
Request
4173E–USB–09/07