Motorola MPC860 PowerQUICC, Руководство пользователя

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Part I. Overview
MOTOROLA Chapter 3. Hardware Interface Overview 3-7
WE0
BS_B0
IORD Output Write Enable 0ÑOutput asserted when a write access to an external slave
controlled by the GPCM is initiated by the MPC860. WE0 is asserted if D[0Ð7]
contains valid data to be stored by the slave device.
Byte Select 0 on UPMBÑOutput asserted under control of the UPMB, as
programmed by the user. In a read or write transfer, the line is only asserted if D[0Ð7]
contains valid data.
IO Device ReadÑOutput asserted when the MPC860 starts a read access to a
region controlled by the PCMCIA interface. Asserted only for accesses to a PC card
I/O space.
WE1
BS_B1
IOWR Output Write Enable 1ÑOutput asserted when the MPC860 initiates a write access to an
external slave controlled by the GPCM. WE1 is asserted if D[8Ð15] contains valid
data to be stored by the slave device.
Byte Select 1 on UPMBÑOutput asserted under control of the UPMB, as
programmed by the user. In a read or write transfer, the line is only asserted if
D[8Ð15] contains valid data.
I/O Device WriteÑThis output is asserted when the MPC860 initiates a write access
to a region controlled by the PCMCIA interface. IOWR is asserted only if the access
is to a PC card I/O space.
WE2
BS_B2
PCOE Output Write Enable 2ÑOutput asserted when the MPC860 starts a write access to an
external slave controlled by the GPCM. WE2 is asserted if D[16Ð23] contains valid
data to be stored by the slave device.
Byte Select 2 on UPMBÑOutput asserted under control of the UPMB, as
programmed by the user. In a read or write transfer, BS_B2 is asserted only
D[16Ð23] contains valid data.
PCMCIA Output EnableÑOutput asserted when the MPC860 initiates a read access
to a memory region under the control of the PCMCIA interface.
WE3
BS_B3
PCWE Output Write Enable 3ÑOutput asserted when the MPC860 initiates a write access to an
external slave controlled by the GPCM. WE3 is asserted if D[24Ð31] contains valid
data to be stored by the slave device.
Byte Select 3 on UPMBÑOutput asserted under control of the UPMB, as
programmed by the user. In a read or write transfer, BS_B3 is asserted only if
D[24Ð31] contains valid data.
PCMCIA Write EnableÑOutput asserted when the MPC860 initiates a write access
to a memory region under control of the PCMCIA interface.
BS_A[0Ð3] Output Byte Select 0 to 3 on UPMAÑOutputs asserted under requirement of the UPMB, as
programmed by the user. For read or writes, asserted only if their corresponding
data lanes contain valid data:
BS_A0 for D[0Ð7], BS_A1 for D[8Ð15],
BS_A2 for D[16Ð23], BS_A3 for D[24Ð31]
GPL_A0
GPL_B0 Output General-Purpose Line 0 on UPMAÑThis output reßects the value speciÞed in the
UPMA when an external transfer to a slave is controlled by the UPMA.
General-Purpose Line 0 on UPMBÑThis output reßects the value speciÞed in the
UPMB when an external transfer to a slave is controlled by the UPMB.
OE
GPL_A1
GPL_B1 Output Output EnableÑOutput asserted when the MPC860 initiates a read access to an
external slave controlled by the GPCM.
General-Purpose Line 1on UPMAÑThis output reßects the value speciÞed in the
UPMA when an external transfer to a slave is controlled by UPMA.
General-Purpose Line 1 on UPMBÑThis output reßects the value speciÞed in the
UPMB when an external transfer to a slave is controlled by UPMB.
Table 3-1. Signal Descriptions (Continued)
Name Type Description