IA82527 Datasheet, PDF (23/45 Pages) InnovASIC, Inc – Serial Communications Controller CAN Protocol

IA82527
CAN Serial Communications Controller
As of Production Ver. 00
04 May 2007
PRELIMINARY
4.1.4 I/O Ports
The IA82527 provides two 8-bit low-speed input/output (I/O) ports. Depending on the CPU
interface mode selected, at least 7 and up to 16 I/O lines are available. Each I/O line is
individually programmable to function either as an input or an output.
4.1.5 Programmable Clock Output
Using an oscillator, clock divider register, and a driver circuit, the IA82527 provides a
programmable clock output. The output frequency range available is from the external crystal
frequency to that frequency divided by 15. The clock output allows the IA82527 to drive other
devices such as the host CPU.
4.2 Address Map
The IA82527 includes 256 8-bit locations that provide device configuration registers and
message storage. The address map is shown in Figure 5.
4.3 CAN Message Objects
Each CAN message object has a unique identifier and can be configured as either transmit or
receive, except for the last message object. The last message object is a receive-only buffer
with a special mask design to allow select groups of different message identifiers to be received.
Each message object contains control and status bits.
All message objects have separate transmit and receive interrupts and status bits that allow the
host CPU to determine when a message frame has been sent or received. The IA82527
implements a global masking feature that allows the user to globally mask any identifier bits of
the incoming message. This mask is programmable, which permits application-specific
message identification.
The Message Object Structure is shown in Figure 6.
Copyright  2007
©
EN21070504-00
Page 23 of 45
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