MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor
12-9
When configured for external arbitration, BR is output only and is asserted by the EBI when it is requesting
the bus. The EBI negates BR as soon as it is granted the bus and the bus is not busy, provided it has no
other internal requests pending. If more requests are pending, the EBI keeps BR asserted as long as needed.
NOTE
The MPC5553 does not implement BR, thus for this device the ball’s
primary function is the calibration address CAL_ADDR[10].
12.2.1.6
Clockout (CLKOUT)
CLKOUT is a general-purpose clock output signal to connect to the clock input of SDR external memories
and in some cases to the input clock of another MCU in multi-master configurations.
12.2.1.7
Chip Selects 0–3 (CS[0:3])
CSx is asserted by the master to indicate that this transaction is targeted for a particular memory bank.
The chip selects are driven by the EBI or an external master depending on who owns the external bus. CS
is driven in the same clock as the assertion of TS and valid address, and is kept valid until the cycle is
terminated. See
Section 12.4.1.5, “Memory Controller with Support for Various Memory Types
” for
details on chip select operation.
12.2.1.8
Calibration Chip Selects 0, 2-3 (CAL_CS [0], CAL_CS [2:3]) — MPC5553
Only
CAL_CSx is asserted by the master to indicate that this transaction is targeted for a particular memory
bank on the calibration external bus.
The calibration chip selects are driven only by the EBI. External master accesses on the calibration bus are
not supported. In all other aspects, the calibration chip selects behave exactly as the primary chip selects.
See
Section 12.4.1.5, “Memory Controller with Support for Various Memory Types
for details on chip
select operation.
12.2.1.9
Data Lines 0–31 (DATA[0:31])
In the 416-pin package of the MPC5553 and the MPC5554, the DATA[0:31] signals contain the data to be
transferred for the current transaction. In the 324-pin package of the MPC5553, DATA[0:15] carry the
data.
DATA[0:31] is driven by the EBI when it owns the external bus and it initiates a write transaction to an
external device. The EBI also drives DATA[0:31] when an external master owns the external bus and
initiates a read transaction to an internal module.
DATA[0:31] is driven by an external device during a read transaction from the EBI. An external master
drives DATA[0:31] when it owns the bus and initiates a write transaction to an internal module or shared
external memory.
For 8-bit and 16-bit transactions, the byte lanes not selected for the transfer do not supply valid data.
NOTE
In the MPC5553, the calibration bus shares DATA[16:31] with the EBI’s
primary bus.
Содержание MPC5553
Страница 5: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 2 Freescale Semiconductor...
Страница 21: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 xvi Freescale Semiconductor...
Страница 47: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 1 26 Freescale Semiconductor...
Страница 163: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 4 20 Freescale Semiconductor...
Страница 179: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 5 16 Freescale Semiconductor...
Страница 561: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 13 38 Freescale Semiconductor...
Страница 615: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 14 54 Freescale Semiconductor...
Страница 707: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 17 68 Freescale Semiconductor...
Страница 755: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 18 48 Freescale Semiconductor...
Страница 873: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 19 118 Freescale Semiconductor...
Страница 984: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 Freescale Semiconductor 21 41...
Страница 985: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 21 42 Freescale Semiconductor...
Страница 1019: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 22 34 Freescale Semiconductor...
Страница 1129: ...MPC5553 MPC5554 Microcontroller Reference Manual Rev 5 25 90 Freescale Semiconductor...
Страница 1207: ...Revision History 4 Freescale Semiconductor...