Z8F042AHJ020SC00TR Zilog, Z8F042AHJ020SC00TR Datasheet - Page 137

• Manufacturer Part Number: Z8F042AHJ020SC00TR
• Description: IC ENCORE XP MCU FLASH 4K 28SSOP
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F042AHJ020SC00TR

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: IrDA, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, LVD, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Z8F042AHJ020SC00T

PS022825-0908
Note:
ADC comp
Factory Calibration
Devices that have been factory calibrated contain 30 bytes of calibration data in the Flash
option bit space. This data consists of 3 bytes for each input mode, one for offset and two
for gain correction. For a list of input modes for which calibration data exists, see
Calibration Data
User Calibration
If you have precision references available, its own external calibration can be performed
using any input modes. This calibration data takes into account buffer offset and non-lin-
earity, so it is recommended that this calibration be performed separately for each of the
ADC input modes planned for use.
Manual Offset Calibration
When uncalibrated, the ADC has significant offset (see
quently, manual offset calibration capability is built into the block. When the
trol Register 0
CALIBRATION mode, the differential inputs to the ADC are shorted together by an inter-
nal switch. Reading the ADC value at this point produces 0 in an ideal system. The value
actually read is the ADC offset. This value can be stored in non-volatile memory (see
Non-Volatile Data Storage
input offset error. There is no provision for manual gain calibration.
Software Compensation Procedure Using Factory Calibration Data
The value read from the ADC high and low byte registers is uncompensated. The user
mode software must apply gain and offset correction to this uncompensated value for
maximum accuracy. The following equation yields the compensated value:
where GAINCAL is the gain calibration value, OFFCAL is the offset calibration value and
ADC
plement format.
The offset compensation is performed first, followed by the gain compensation. One
bit of resolution is lost because of rounding on both the offset and gain computations.
As a result the ADC registers read back 13 bits: 1 sign bit, two calibration bits lost to
rounding and 10 data bits.
Also note that in the second term, the multiplication must be performed before the
division by 2
uncomp
=
is the uncompensated value read from the ADC. All values are in two’s com-
(
sets the input mode (
ADC uncomp OFFCAL
16
on page 161.
. Otherwise, the second term incorrectly evaluates to zero.
on page 169) and accessed by user code to compensate for the
–
ANAIN[2:0]
)
+
(
(
ADC uncomp OFFCAL
) to MANUAL OFFSET
Z8 Encore! XP
Table 135
–
Product Specification
Analog-to-Digital Converter
on page 231). Subse-
)
®
×
GAINCAL
F082A Series
ADC Con-
Zilog
)
⁄
2
16
126