
MB91460P Series
DS07-16615-2E
39
■ A/D CONVERTER / NEW FEATURES (MB91F467PA)
MB91F467PA has two 10-bit A/D Converter macros. The original ADC, which is available on all MB91460 series
devices, is now called “ADC 0”, the second macro is called “ADC 1”.
1.
A/D Converter Features
Both ADC 0 and ADC 1 are 10-bit / 1
μs macros used on other MB91460 series devices.
Both ADCs have the new digital part with separated A/D Result registers and 4-channel Range Comparator,
Both ADCs can be triggered from Reload Timer RLT7.
Both ADCs can be triggered from the same external ATGX pin (GP16_7).
On MB91F467PA, ADC0 and ADC1 share the same analog power and reference supply (AVCC5,AVRH5,AVSS).
2.
Analog Input Connections
2.1.
Global ADC Analog Channel Enable
The global ADC channel enable feature makes the ADC analog inputs independend of PFR/EPFR settings. It was
introduced for 2 reasons:
Some new ADC channels are assigned to ports whose PFR/EPFR combinations are already used completely
for other resources.
Customers may measure digital output signals with the ADC to check for external shortages.
PFR/EPFR settings for ADC always switch the digital port to HiZ mode.
The global ADC channel enable is controlled by bit ADCHE in PORTEN register:
PORTEN Register Address: 0x0498 Access: Byte
Bit7-3: Reserved bits. Always write 0 to these bits.
Bit2: ADCHE Global A/D Channel Enable.
This bit is cleared by software reset (RST) and can be written and read by CPU.
Note: For new ADC channels (AN32 to AN53, device depending), the ADCHE feature is always ON.
For old ADC channels (AN0 to AN31), the ADCHE feature is always OFF if the channels are re-located to
other pins. On MB91F467PA, the ADCHE feature is only available on the non-relocated ADC channels 6-7
on ports P29[6,7].
76543
2
1
0
Bit
-----
ADCHE CPORTEN GPORTEN
XXXXX
0
Initial value
RX, W0 RX, W0 RX, W0 RX, W0 RX, W0
R, W
Attribute
ADCHE
Function
0 [initial]
Global A/D Channel Enable is OFF.
The ADC analog lines of channels 0-31 are enabled by setting of the ADC enable bits (ADEn)
in the ADERH,ADERL register and PFR/EPFR. PFR/EPFR will set the digital output to HiZ
mode and disable the digital input lines of the port.
1
Global A/D Channel Enable is ON.
The ADC analog lines of channels 6-7 are enabled by setting of the ADC enable bits (ADEn)
in the ADERH,ADERL register only. ADEn will disable the digital input lines of the port, but
the digital outputs are not changed. For analog measurement, the user has to switch the port
to input direction.