and one DAC device in parallel. Address and data signals unused by the ADC and the
DAC can be use for general purpose input output, providing 0, 8, 16 or 24 channels.
The ADC interface supports 8 and 16 bit data widths. It provides chip select, read/con-
vert and ready signals. The timing is programmable. It also provides an 8-bit address
output. The ADC conversion can be initiated either via the AMBA interface or by internal
or external triggers. An interrupt is generated when a conversion is completed.
The DAC interface supports 8 and 16 bit data widths. It provides a write strobe signal.
The timing is programmable. It also provides an 8-bit address output.
4.7
4.8
32-bit Timers
The SpaceWire-RTC includes a General Purpose Timer Unit that implements one pres-
caler and two 32-bit decrementing timers.
24-bit General Purpose Input Output
The SpaceWire-RTC includes a 24-bit General Purpose Input Output core. The AMBA
APB bus is used for control and status handling.
The core provides 24 channels. Each channel is individually programmed as input or
output. Additionally, 8 of the channels are also programmable as pulse command out-
puts. The default reset configuration for each channel is as input. The default reset
value each channel is logical zero.
The pulse command outputs have a common 20-bit counter for establishing the pulse
command length. The pulse command length defines the logical one (active) part of the
pulse. It is possible to select which of the channels shall generate a pulse command.
The pulse command outputs are generated simultaneously in phase with each other,
and with the same length (or duration). It is not possible to generate pulse commands
out of phase with each other.
4.9
CAN Interface
The SpaceWire-RTC includes a CAN controller. The CAN protocol is based on the ESA
HurriCANe CAN Controller VHDL core.
The controller uses the AMBA APB bus for configuration, control and status handling.
The AMBA AHB bus is used for retrieving and storing CAN messages in memory exter-
nal to the CAN controller. This memory can be located on-chip or external to the chip.
The CAN controller supports transmission and reception of sets of messages by use of
circular buffers located in memory external to the core. Separate transmit and receive
buffers are assumed. Reception and transmission of sets of messages can be ongoing
simultaneously.
4.10 SpaceWire Link Interface
The SpaceWire (SPW2) Module is used for transmitting and receiving data over a
SpaceWire link. It provides support for transmitting any type of protocol or data structure
using SpaceWire packets.
12
AT7913E
7833F–AERO–01/10
ATMEL [ ATMEL ]
