
Introduction
1-3
GMS30C7201 Data Sheet
may be used as a CompactFlash interface. The PC-Card interface supports the 16-bit
slave-only interface, with no DMA support. It does not support the CardBus 32-bit bus
master option in the standard.
1.1.5 Peripherals and communications
Communications are well-catered for, by two UARTs, an IrDA interface (supporting
slow, medium and fast protocols), a serial interface to a modem CODEC chip, for use
by the soft-modem, and an on-chip keyboard controller, which directly scans the key
matrix. One of the two UARTs is used to implement the IrDA protocol. If IrDA is not
being used, then this UART is available for general use. A synchronous serial interface
allows connection to a variety of devices, such as an RF modem or a Multimedia Card.
A slave USB port supports connection of an GMS30C7201-based PDA as a peripheral
to a PC or other USB host controller. A group of general purpose I/O pins can be utilized
as required in a PDA design. An on-chip DAC supports audio output, and an on-chip
ADC supports microphone input, the digitizer tablet and battery status monitoring
functions. Internally, three general-purpose timers and a real-time clock provide timer
functionality to be used as required by the O/S, and a two-channel general purpose
DMA controller can be allocated to the communications peripherals, as required.
1.1.6 Power management
The GMS30C7201 incorporates advanced power management functions, allowing the
whole device to be put into a standby mode, when only the real time clock runs. The
SDRAM is put into low-power self refresh mode to preserve it
’
s contents. The
GMS30C7201 may be forced out of this state by either a real-time clock wake-up
interrupt, a user wake-up event (which would generally be a user pressing the
“
on
”
key)
or by the UART ring-indicate input. The power management unit (PMU) controls the
safe exit from standby mode to operational mode, ensuring that SDRAM contents are
preserved. In addition, halt and slow modes allow the processor to be halted, or run
more slowly than usual, to reduce power consumption. The processor can be quickly
brought out of the halted state by a peripheral interrupt. The advanced power
management unit controls all this functionality. In addition, individual devices and
peripherals may be powered down when they are not in use. For example, the VGA
controller can be disabled when an external monitor is not in use (which saves not only
the power of the digital controller, but also of the analog DACs), or the Piccolo DSP
coprocessor can be powered-down when DSP support (in soft-modem code, for
example) is not required.
1.1.7 Test and debug
The GMS30C7201 incorporates the ARM standard test interface controller (TIC)
allowing 32-bit parallel test vectors to be passed onto the internal bus. This allows
access to the ARM720T macro-cell core, and also to memory mapped devices and
peripherals within the GMS30C7201. In addition, the ARM720T and Piccolo include
support for the ARM debug architecture (Embedded ICE), which makes use of a JTAG
boundary scan port to support debug of code on the embedded processor and DSP
cores. The same boundary scan port is also used to support a normal pad-ring
boundary scan for board level test applications.