T89C5115_08 ATMEL [ATMEL Corporation], T89C5115_08 Datasheet - Page 84

• Manufacturer Part Number: T89C5115_08
• Description: Low Pin Count 8-bit Microcontroller with A/D Converter and 16 KBytes Flash Memory
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 38. ADC Description
Figure 39. Timing Diagram
Note:
ADC Converter
Operation
84
Tsetup min, see the AC Parameter for A/D conversion.
Tconv = 11 clock ADC = 1sample and hold + 10-bit conversion
The user must ensure that Tsetup time between setting ADEN and the start of the first conversion.
AN0/P1.0
AN1/P1.1
AN2/P1.2
AN3/P1.3
AN4/P1.4
AN5/P1.5
AN6/P1.6
AN7/P1.7
AT89C5115
ADEOC
ADSST
ADEN
CLOCK
CLK
ADC
ADCON.2
SCH2
000
001
010
011
100
101
110
111
T
SETUP
ADCON.1
SCH1
Figure 39 shows the timing diagram of a complete conversion. For simplicity, the figure
depicts the waveforms in idealized form and do not provide precise timing information.
For ADC characteristics and timing parameters refer to the section “AC Characteristics”
of this datasheet.
A start of single A/D conversion is triggered by setting bit ADSST (ADCON.3).
After completion of the A/D conversion, the ADSST bit is cleared by hardware.
The end-of-conversion flag ADEOC (ADCON.4) is set when the value of conversion is
available in ADDH and ADDL, it must be cleared by software. If the bit EADC (IEN1.1) is
set, an interrupt occur when flag ADEOC is set (See Figure 41). Clear this flag for re-
arming the interrupt.
Note:
ADCON.5
Sample and Hold
ADEN
CONTROL
ADCON.0
SCH0
Always leave Tsetup time before starting a conversion unless ADEN is permanently high.
In this case one should wait Tsetup only before the first conversion
Rai
Cai
ADCON.3
ADSST
AVSS
ADCIN
+
-
T
CONV
VAREF
ADCON.4
ADEOC
R/2R DAC
VAGND
SAR
EADC
IEN1.1
10
8
2
ADDH
ADDL
ADC
Interrupt
Request
4128G–8051–02/08