HT82A520R HOLTEK [Holtek Semiconductor Inc], HT82A520R Datasheet - Page 35

• Manufacturer Part Number: HT82A520R
• Description: Full Speed USB 8-Bit OTP MCU with SPI
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

poll the EOCB bit in the ADCR register to check whether
it has been cleared as an alternative method of detect-
ing the end of an A/D conversion cycle.
A/D Converter Clock Source Register - ACSR
The clock source for the A/D converter, which originates
from the system clock f
ratio, the value of which is determined by the ADCS1
and ADCS0 bits in the ACSR register.
The ACSR control register also contains the
PCR3~PCR0 bits which determine which pins on Port B
and Port C are used as analog inputs for the A/D con-
verter and which pins are to be used as normal I/O pins.
If the 4-bit address on PCR3~PCR0 has a value of
Rev.1.00
SYS
, is first divided by a division
A/D Converter Clock Source Register
A/D Converter Control Register
35
all be set as analog inputs. Note that if the PCR3~PCR0
bits are all set to zero, then all the Port B and Port C pins
will be setup as normal I/Os and the internal A/D con-
verter circuitry will be powered off to reduce the power
consumption.
Although the A/D clock source is determined by the sys-
tem clock f
some limitations on the maximum A/D clock source speed
that can be selected. As the minimum value of permissible
A/D clock period, t
tem clock speeds in excess of 4MHz. For system clock
speeds in excess of 4MHz, the ADCS1 and ADCS0 bits
should not be set to 00 . Doing so will give A/D clock peri-
1111 or higher, then all 16 pins, namely AN0~ AN15 will
SYS
, and by bits ADCS1 and ADCS0, there are
HT82A520R/HT82A620R
AD
, is 0.5 s, care must be taken for sys-
October 23, 2009