External Signals
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 6-7
WT
BADDR30
IRQ3
Write through—Output used for L2 cache control. For each core-initiated PowerQUICC II 60x
transaction, the state of this pin indicates if the transaction should be cached using write-through
or copy-back mode. Assertion of WT indicates that the transaction should be cached using the
write-through mode.
Burst address 30—There are five burst address output pins. These pins are outputs of the 60x
memory controller. These pins are used in external master configuration and are connected
directly to memory devices controlled by PowerQUICC II’s memory controller. For information on
the use of this signal, see Section11.2.14, “BADDR[27:31] Signal Connections.”
Interrupt request 3—This input is one of the eight external lines that can request (by means of the
internal interrupt controller) a service routine from the core.
L2_HIT
IRQ4
L2 cache hit—(Input) It is used for L2 cache control. Assertion of this pin indicates that the 60x
transaction will be handled by the L2 cache. In this case, the memory controller will not start an
access to the memory it controls.
Interrupt request 4—This input is one of the eight external lines that can request (by means of the
internal interrupt controller) a service routine from the core.
CPU_BG
BADDR31
IRQ5
CPU bus grant—(Output) The value of the 60x core bus grant is driven on this pin to be used by
an external MPC2605GA L2 cache. The driven bus grant is not qualified; that is, when using an
external arbiter, the user should qualify this signal with the bus grant input to the PowerQUICC II
before connecting it to the L2 cache.
Burst address 31—There are five burst address output of the 60x memory controller used in an
external master configuration and are connected directly to the memory devices controlled by
PowerQUICC II’s memory controller. For information on the use of this signal, see
Section11.2.14, “BADDR[27:31] Signal Connections.”
Interrupt Request 5—This input is one of the eight external lines that can request (by means of
the internal interrupt controller) a service routine from the core.
CPU_DBG CPU data bus grant—(Output) Valid only when using the internal arbiter (PPC_ACR[EARB]= 0).
The OR of all data bus grant signals for internal masters from the internal arbiter is driven on
CPU_DBG. CPU_DBG should be connected to the CPU DBG input of an external MPC2605GA
L2 cache. (If an external arbiter is used, the CPU DBG input of the external MPC2605GA L2
cache should be connected to the DBG driven from the external arbiter to this PowerQUICC II.)
CPU_BR CPU bus request—(Output) The value of the 60x core bus request is driven on this pin for the use
of an external L2 cache.
CS[0–9] Chip select—These are output pins that enable specific memory devices or peripherals
connected to PowerQUICC II buses.
CS[10]
BCTL1
Chip select—These are output pins that enable specific memory devices or peripherals
connected to PowerQUICC II buses.
Buffer control 1—Output signal whose function is controlling buffers on the 60x data bus. Usually
used with BCTL0. The exact function of this pin is defined by the value of SIUMCR[BCTLC]. See
Section4.3.2.6, “SIU Module Configuration Register (SIUMCR),” for details.
Table6-1. External Signals (continued)
Signal Description