4.5 USER STATUS SIGNALS

• OATT - Attached.
  This signal goes high during a Primary Address Cycle that the Slave recognizes. It may be used to drive the Activity Indicator via a pulse length stretching circuit.

• OBPS - Block/Pipeline Sequence.
  OBPS is high when the last operation was a Block or Pipelined Transfer, and the present operation is a Block or Pipelined operation. It is cleared by Power-on-clear, detaching, or any operation other than Block or Pipelined. OBPS can be used by the user's NTA decoder to indicate ``end-of-block'' at any address, even if that address is otherwise valid. See Section 11.1 for an application note.

• OCC(3:0) - Connection Code.
  These lines indicate the mode of attachment of the Slave; see Table 5. See section 11.11 for an application note.

  

  

• OCND - Control/Not Data.
  The latched state of MS0 received at a recognised Primary Address time. This is used by the user's NTA decoder to select CSR or Data space.

• OMS(2:0) - Latched Mode Select, ORD Latched Read.
  At the start of each Data transfer operation the state of MS(2:0) and RD are latched, and are presented to the user for NTA decoding or any other purpose, such as Multiblock logic.

• OSA - Secondary Address.
  When high, indicates that a secondary address cycle is in progress. OSA is intended for use in the users address decoder to declare locations as read-only, etc. See Section 11.2 for applications.

• OUST - User Strobe.
  When high, indicates that the user RAM, FIFO registers, other externally implemented CSRs (but not CSR#0) should either be written or read, depending on the state of ORD.