Communication Block
UG0331 User Guide Revision 15.0
599
Note:
The system IP interface (SII) master connects the System Controller with all the internal elements. It is
used to transfer data to and from the MSS memory space by the System Controller for System Services.
It is also used for factory test but not available for customer.
17.5.3
Interrupt Enable Register
This register enables the COMMS_INT to be set whenever the corresponding bit is set in the
register.
17.5.4
Byte Data Register
This register writes a byte to the Transmit FIFO or reads a byte from the Receive FIFO. If the Transmit
FIFO is full at the time of a write, an OVERFLOW will be set in the STATUS register. Similarly, if Receive
FIFO is empty at the time of a read, an UNDERFLOW will be generated.
When the
register is written, the command bit (Bit 8 on DATA) is set to 0, indicating that it is data.
Writes to this register automatically set the SIZETX to 0 (1 byte), and reads set the SIZERX to 0 (1 byte).
4
SIIDONE
R/W
0
Indicated that the transfer to SII Bus is complete.
Write 1 to clear
3
UNDERFLOW R/W
0
Receive Overflow. Indicates that the receive FIFO was read when empty.
Write 1 to clear
2
OVERFLOW
R/W
0
Transmit Overflow. Indicates that the Transmit FIFO was written when full.
Write 1 to clear
1
RCVOKAY
R
0
RCV FIFO non empty. Indicates that 1 or 4 bytes may be read based on
SIZERX.
0
TXTOKAY
R
1
TXT FIFO non full. Indicates that 1 or 4 bytes may be written depending on
SIZETX.
Table 596 •
INT_ENABLE
Bit
Number
Name
R/W
Reset
Value Description
[7:0]
ENABLE
R/W
0x00
Matches corresponding bit in status register
0: Disables Interrupt
1: Enables Interrupt
Table 597 •
DATA8
Bit
Number
Name
R/W
Reset
Value
Description
[7:0]
DATA8
R/W
0x00
Write: Writes a byte to the MSS COMM_BLK Transmit FIFO
Read: Reads a byte from the MSS COMM_BLK Receive FIFO
Table 595 •
STATUS
(continued)