Fast AMBA Peripherals
12-69
GMS30C7201 Data Sheet
12.11.1Hardware interface and signal description
The SOC module is connected to the internal APB bus.
Name
Type
Source/
Destination
Description
PCLK
In
Clock controller
UART clock (3.6864MHz).
BnRES
In
APB Bridge
Reset signal generated from the APB Bridge.
PA[4:2]
In
APB Bridge
This is the peripheral address bus, which is used by an individual
peripheral for decoding register accesses to that peripheral.
The addresses become valid before PSTB goes HIGH, and remain valid
after PSTB goes LOW.
PD[31:0]
InOut
APB Peripherals,
BD bus
This is the bidirectional peripheral data bus. The data bus is driven by this
block during read cycles (when PWRITE is LOW).
PSTB
In
APB Bridge
This strobe signal is used to time all accesses on the peripheral bus. The
falling edge of PSTB is coincident with the falling edge of BCLK.
PWRITE
In
APB Bridge
When HIGH, this signal indicates a write to a peripheral. When LOW, it
indicates a read from a peripheral.
This signal has the same timing as the peripheral address bus. It becomes
valid before PSTB goes HIGH, and remains valid after PSTB goes LOW.
PSEL
In
APB Bridge
When HIGH, this signal indicates that this module has been selected by
the APB bridge. This selection is a decode of the system address bus
(ASB).
For more details, see
AMBA Peripheral Bus Controller
(ARM DDI0044).
PSELDMA
In
APB Bridge
Active HIGH signal provided by the APB Bridge to indicate SoundC DMA
access.
DRQ
Out
DMA
When SD transfers upper 16-bit, this signal requests more sound data for
the DAC with active HIGH until writing the data at SDADR.
INT
Out
Interrupt
Controller
When SD transfer upper 16-bit, this signal requests more sound data for
the DAC with active HIGH until writing the data at SDADR.
SD[7:0]
Out
DAC
DAC data bus. During SCLK HIGH, it is upper 8-bit of DataBuf, and during
LOW, the lower 8-bit of DataBuf.
IOSTOP
Out
DAC
When HIGH, analog circuits in DAC go to rail-to-rail to save power
dissipation. If inactive LOW, the analog circuit in the DAC operates in
normal mode.
DLEFT
Out
DAC
When HIGH, this signal indicates that converted left data out is stable in
DAC. Left/right signal is non-overlapping signal.
DRIGHT
Out
DAC
When HIGH, this signal indicates that converted right data out is stable in
DAC.
Table 12-43: APB signal descriptions