UPD78F0034BGC-8BS-A Renesas Electronics America, UPD78F0034BGC-8BS-A Datasheet - Page 286

• Manufacturer Part Number: UPD78F0034BGC-8BS-A
• Description: MCU 8-Bit 78K0 CISC 32KB Flash 2.5V/3.3V/5V 64-Pin LQFP
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0034BGC-8BS-A

• Package: 64LQFP
• Family Name: 78K0
• Maximum Speed: 12 MHz
• Ram Size: 1 KB
• Program Memory Size: 32 KB
• Operating Supply Voltage: 2.5|3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 51
• Interface Type: 3-Wire/UART
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

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14.4 A/D Converter Operation
14.4.1 Basic operations of A/D converter
<1> Select one channel for A/D conversion with analog input channel specification register 0 (ADS0).
<2> The voltage input to the selected analog input channel is sampled by the sample & hold circuit.
<3> When sampling has been done for a certain time, the sample & hold circuit is placed in the hold state and
<4> Bit 9 of the successive approximation register (SAR) is set. The series resistor string voltage tap is set to
<5> The voltage difference between the series resistor string voltage tap and analog input is compared by the
<6> Next, bit 8 of SAR is automatically set, and the operation proceeds to the next comparison. The series resistor
<7> Comparison is continued in this way up to bit 0 of SAR.
<8> Upon completion of the comparison of 10 bits, an effective digital result value remains in SAR, and the result
Cautions 1. The first A/D conversion value immediately after A/D conversion has been started may not
the input analog voltage is held until the A/D conversion operation is ended.
(1/2) AV
voltage comparator. If the analog input is greater than (1/2) AV
input is smaller than (1/2) AV
string voltage tap is selected according to the preset value of bit 9, as described below.
• Bit 9 = 1: (3/4) AV
• Bit 9 = 0: (1/4) AV
The voltage tap and analog input voltage are compared and bit 8 of SAR is manipulated as follows.
• Analog input voltage
• Analog input voltage < Voltage tap: Bit 8 = 0
value is transferred to and latched in A/D conversion result register 0 (ADCR0).
At the same time, the A/D conversion end interrupt request (INTAD0) can also be generated.
2. The A/D converter stops operation in standby mode.
REF
satisfy the rated value. Take measures such as polling the A/D conversion end interrupt
request (INTAD0) and removing the first conversion results.
CHAPTER 14 10-BIT A/D CONVERTER ( PD780034A, 780034AY SUBSERIES)
by the tap selector.
REF
REF
Voltage tap: Bit 8 = 1
REF
, the MSB is reset.
User’s Manual U14046EJ5V0UD
REF
, the MSB of SAR remains set. If the analog