6 voltage reference signals, 7 dedicated analog supply signals, 8 dedicated digital i/o port supply signal – Motorola ColdFire MCF5281 User Manual
Page 544: 5 memory map, 5 memory map -6

Queued Analog-to-Digital Converter (QADC)
28-6
Freescale Semiconductor
28.4.6
Voltage Reference Signals
V
RH
and V
RL
are the dedicated input signals for the high and low reference voltages. Separating the
reference inputs from the power supply signals allows for additional external filtering, which increases
reference voltage precision and stability, and subsequently contributes to a higher degree of conversion
accuracy.
NOTE
V
RH
and V
RL
must be set to V
DDA
and V
SSA
potential, respectively. For
more information, refer to
Section 28.9, “Signal Connection
28.4.7
Dedicated Analog Supply Signals
The V
DDA
and V
SSA
signals supply power to the analog subsystems of the QADC module. Dedicated
power is required to isolate the sensitive analog circuitry from the normal levels of noise present on the
digital power supply.
28.4.8
Dedicated Digital I/O Port Supply Signal
V
DDH
provides 5-V power to the digital I/O functions of QADC port QA and port QB. This allows those
signals to tolerate 5 volts when configured as inputs and drive 5 volts when configured as outputs.
28.5
Memory Map
The QADC occupies 1 Kbyte, or 512 half-word (16-bit) entries, of address space. Ten half-word registers
are control, port, and status registers, 64 half-word entries are the CCW table, and 64 half-word entries are
the result table which occupies 192 half-word address locations because the result data is readable in three
data alignment formats.
is the QADC memory map.
Table 28-2. QADC Memory Map
IPSBAR +
Offset
MSB
LSB
Access
1
0x19_0000
QADC Module Configuration Register (QADCMCR)
S
0x19_0002
QADC Test Register (QADCTEST)
2
S
0x19_0004
Reserved
3
—
0x19_0006
Port QA Data Register (PORTQA)
Port QB Data Register (PORTQB)
S/U
0x19_0008
Port QA Data Direction Register
(DDRQA)
Port QB Data Direction Register
(DDRQB)
S/U
0x19_000a
QADC Control Register 0 (QACR0)
S/U
0x19_000c
QADC Control Register 1 (QACR1)
S/U
0x19_000e
QADC Control Register 2 (QACR2)
S/U
0x19_0010
QADC Status Register 0 (QASR0)
S/U
0x19_0012
QADC Status Register 1 (QASR1)
S/U
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3