ADUC814BRU Analog Devices Inc, ADUC814BRU Datasheet - Page 48

• Manufacturer Part Number: ADUC814BRU
• Description: A/D Converter (A-D) IC
• Manufacturer: Analog Devices Inc
• Series: MicroConverter® ADuC8xxr

Specifications of ADUC814BRU

• Peak Reflow Compatible (260 C): No
• No. Of Bits: 12 Bit
• Leaded Process Compatible: No
• Mounting Type: Surface Mount
• No. Of Inputs: 6
• Features: +3V Or +5V Operation
• Package / Case: 28-TSSOP
• Rohs Status: RoHS non-compliant
• Core Processor: 8052
• Core Size: 8-Bit
• Speed: 16.78MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PSM, Temp Sensor, WDT
• Number Of I /o: 17
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 640 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x12b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: EVAL-ADUC814QSZ - KIT DEV FOR ADUC814 MICROCONVRTR
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

ADuC814
TIMERS/COUNTERS
The ADuC814 has three 16-bit timer/counters: Timer 0,
Timer 1, and Timer 2. The timer/counter hardware has been
included on-chip to relieve the processor core of the overhead
inherent in implementing timer/counter functionality in
software. Each timer/counter consists of two 8-bit registers,
THx and TLx (x = 0, 1 and 2). All three can be configured to
operate either as timers or event counters.
In timer function, the TLx register is incremented every
machine cycle. Thus one can think of it as counting machine
cycles. Since a machine cycle consists of 12 core clock periods,
the maximum count rate is 1/12 of the core clock frequency.
In counter function, the TLx register is incremented by a 1-to-0
transition at its corresponding external input pin, T0, T1, or T2.
In this function, the external input is sampled during S5P2 of
every machine cycle. When the samples show a high in one
cycle and a low in the next cycle, the count is incremented. The
new count value appears in the register during S3P1 of the cycle
Table 22. TMOD SFR Bit Designations
Bit
7
6
5
4
3
2
1
0
GATE
Name
GATE
C/T
M1
M0
Gate
C/ T
M1
M0
Description
Timer 1 Gating Control.
Set by software to enable Timer/Counter 1 only while INT1 pin is high and TR1 control bit is set.
Cleared by software to enable Timer 1 whenever TR1 control bit is set.
Timer 1 Timer or Counter Select Bit.
Set by software to select counter operation (input from T1 pin).
Cleared by software to select timer operation (input from internal system clock).
Timer 1 Mode Select Bit 1 (Used with M0 Bit).
Timer 1 Mode Select Bit 0.
M1
0
0
1
1
Timer 0 Gating Control.
Set by software to enable Timer/Counter 0 only while INT0 pin is high and the TR0 control bit is set.
Cleared by software to enable Timer 0 whenever the TR0 control bit is set.
Timer 0 Timer or Counter Select Bit.
Set by software to select counter operation (input from T0 pin).
Cleared by software to select timer operation (input from internal system clock).
Timer 0 Mode Select Bit 1.
Timer 0 Mode Select Bit 0.
M1
0
0
1
1
M0
0
1
0
1
M0
0
1
0
1
C/T
TH1 operates as an 8-bit timer/counter. TL1 serves as 5-bit prescaler.
16-Bit Timer/Counter. TH1 and TL1 are cascaded; there is no prescaler.
8-Bit Auto-Reload Timer/Counter. TH1 holds a value which is to be reloaded into TL1 each time it overflows.
Timer/Counter 1 Stopped.
TH0 operates as an 8-bit timer/counter. TL0 serves as 5-bit prescaler.
16-Bit Timer/Counter. TH0 and TL0 are cascaded; there is no prescaler.
8-Bit Autoreload Timer/Counter. TH0 holds a value which is to be reloaded into TL0 each time it overflows.
TL0 is an 8-bit timer/counter controlled by the standard Timer 0 control bits.
M1
M0
Rev. A | Page 48 of 72
following the one in which the transition was detected. Since it
takes two machine cycles (16 core clock periods) to recognize a
1-to-0 transition, the maximum count rate is 1/16 of the core
clock frequency. There are no restrictions on the duty cycle of
the external input signal, but to ensure that a given level is
sampled at least once before it changes, it must be held for a
minimum of one full machine cycle. Remember that the core
clock frequency is programmed via the CD0–CD2 selection bits
in the PLLCON SFR. User configuration and control of all timer
operating modes is achieved via three SFRs: TMOD, TCON,
and T2CON.
TMOD
SFR Address
Power-On Default
Bit Addressable
GATE
C/T
Timer/Counter 0 and 1 Mode Register
89H
00H
No
M1
M0