NXP Semiconductors LPC2880, User Manual

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User manual Rev. 02 — 1 June 2007 271 of 362
NXP Semiconductors
UM10208
Chapter 21: LPC2800 DADC
6. Simple Analog In (SAI4) module
The Dual ADC SAI is called SAI4. It receives two 24-bit values from the decimator block.
The SAI includes a 4-deep FIFO with each entry containing two 24-bit values. Data can be
read from it by the ARM7 processor or by 1 or 2 DMA channels
6.1 SAI4 registers
Table 21–308 lists the registers in SAI4, two of which are described in greater detail in
subsequent tables.
No further detail of the various IN registers should be necessary. Only the Status and
Mask registers are described below.
Table 308. SAI4 register map
Names Addresses Description Access Reset
Value
L16IN4 0x8020 0180 The MS 16 bits of the oldest L channel value in the
SAI can be read from this register. The value is
removed from the L FIFO by reading this register.
Bits 31:16 read as zero.
RO 0
R16IN4 0x8020 0184 The MS 16 bits of the oldest R channel value in the
SAI can be read from this register. The value is
removed from the R FIFO by reading this register.
Bits 31:16 read as zero.
RO 0
L24IN4 0x8020 0188 The oldest L channel value in the SAI can be read
from this register. The value is removed from the L
FIFO by reading this register. Bits 31:24 read as
zero.
RO 0
R24IN4 0x8020 018C The oldest R channel value in the SAI can be read
from this register. The value is removed from the R
FIFO by reading this register. Bits 31:24 read as
zero.
RO 0
SAISTAT4 0x8020 0190 The current status of the SAI can be read from this
register. Writing any value to this address clears
the underrun and overrun bits in this register.
R/W 0
SAIMASK4 0x8020 0194 1s in this register disable/mask the corresponding
condition in SAISTAT4 from causing an SAI
interrupt request.
R/W 0x3FF
L32IN4 0x8020 01A0 The MS 16 bits of the two oldest L channel values
in the SAI can be read from this register. The
values are removed from the L FIFO by reading this
register. Bits 15:0 contain the older of the two
values.
RO 0
R32IN4 0x8020 01C0 The MS 16 bits of the two oldest R channel values
in the SAI can be read from this register. The
values are removed from the R FIFO by reading
this register. Bits 15:0 contain the older of the two
values.
RO 0
LR32IN4 0x8020 01E0 The MS 16 bits of the oldest L channel value and
the oldest R channel value can be read from this
register. The values are removed from the FIFOs
by reading this register. Bits 15:0 contain the L
channel value.
RO 0