
2000 Nov 17
15
Philips Semiconductors
Preliminary specification
1394 SBP-2 link layer controller
SAA7356HL
Table 2
CmdFromMicro register definition (read/write)
Table 3
Sbp2Start register definition (read/write)
Table 4
CmdToMicro register definition (read/write)
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Command(7:0)
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Command(7:0)
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Command(7:0)
8.3
Interrupt registers
As mentioned in the previous section, the communications
may be interrupt driven. To facilitate this there is one
InterruptReason
and one
InterruptEnable
register. The
interrupt to the microcontroller is of the AND-OR type and
is asserted when any of the maskable interrupts are
enabled and active: to enable an interrupt, the
corresponding field in the
InterruptEnable
register must
be set to logic 1. Reading from the
InterruptReason
register provides the un-masked value: this allows polling
if desired.
The
InterruptEnable
and
InterruptReason
register
definitions are shown in Tables 5 and 6 respectively.
In addition to these two registers, the microcontroller may
set the values in the
InterruptReason
register: this may
be used for setting initial conditions, for example. To set
the required bits, a logic 1 must be written to the flag
location in the
InterruptSet
register: writing a logic 0 to
any bit-field has no effect. The
InterruptSet
register
definition is given in Table 7.
Itisrecommendedthatonlythe
InterruptReason.CmdClr
flag is set as
InterruptReason.CmdMicro
will cause a
maskable interrupt to be asserted to the microcontroller.
The definition of the
InterruptReason
,
InterruptEnable
and the
InterruptSet
register fields are shown in Table 8.
Table 5
InterruptEnable register definition (read/write)
Table 6
InterruptReason register definition (read/write)
Table 7
InterruptSet register definition (write only, read via InteruptReason)
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Reserved
CmdMicro
BusReset
CmdClr
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Reserved
CmdMicro
BusReset
CmdClr
BYTE
NUMBER
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
0
Reserved
CmdMicro
Reserved
CmdClr