K60P100M100SF2RM Datasheet, PDF (698/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Memory Map/Register Definition
Note
When burst (FB_TBST = 0), transfer size is 16 bytes
(FB_TSIZ[1:0] = 11) and the address is misaligned within the
16-byte boundary, the external device must be able to wrap
around the address.
29.2.9 Transfer Acknowledge (FB_TA)
This input signal indicates the external data transfer is complete. When the processor
recognizes FB_TA during a read cycle, it latches the data and then terminates the bus
cycle. When the processor recognizes FB_TA during a write cycle, the bus cycle is
terminated.
If auto-acknowledge is disabled (CSCRn[AA] = 0), the external device drives FB_TA to
terminate the bus transfer; if auto-acknowledge is enabled (CSCRn[AA] = 1), FB_TA is
generated internally after a specified number of wait states, or the external device may
assert external FB_TA before the wait-state countdown, terminating the cycle early. The
device negates FB_CSn one cycle after the last FB_TA asserts. During read cycles, the
peripheral must continue to drive data until FB_TA is recognized. For write cycles, the
processor continues driving data one clock after FB_CSn is negated.
The number of wait states is determined by CSCRn or the external FB_TA input. If the
external FB_TA is used, the peripheral has total control on the number of wait states.
Note
External devices should only assert FB_TA while the FB_CSn
signal to the external device is asserted.
The CSPMCR register controls muxing of FB_TA with other
signals. If auto-acknowledge is not used and CSPMCR does not
allow FB_TA control, the FlexBus may hang.
29.3 Memory Map/Register Definition
The following tables describe the registers and bit meanings for configuring chip-select
operation.
The actual number of chip selects available depends upon the device and its pin
configuration. If the device does not support certain chip select signals or the pin is not
configured for a chip-select function, then that corresponding set of chip-select registers
has no effect on an external pin.
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
698
Freescale Semiconductor, Inc.