Freescale Semiconductor PowerQUICC MPC870, Reference Manual

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PCMCIA Interface
MPC885 PowerQUICC Family Reference Manual, Rev. 2
16-16 Freescale Semiconductor
12–15 PSHT PCMCIA strobe hold time (strobe negation to address negation). Specifies when IOWR_xx or
WE_x are negated during a PCMCIA write or when IORD_x or OE_x are negated during a PCMCIA
read. Used to meet address/data hold time requirements for slow memories and peripherals.
0000 Strobe negation to address change 0 clock
0001 Strobe negation to address change 1 clock
...
1111 Strobe negation to address change 15 clock
16–19 PSST PCMCIA strobe set up time (address to strobe assertion). Specifies when IOWR_x or WE_x are
asserted during a PCMCIA write access or when IORD_x or OE_x are asserted during a PCMCIA
read access handled by the PCMCIA interface. This helps meet address/setup time requirements
for slow memories and peripherals.
0000 Reserved
0001 Address to strobe assertion 1 clock cycle
0010 Address to strobe assertion 2 clock cycles
...
1111 Address to strobe assertion 15 clock cycles
20–24 PSL PCMCIA strobe length. Determines the number of cycles the strobe is asserted during a PCMCIA
access for this window and, thus, it is the main parameter for determining cycle length. The cycle
may be lengthened by asserting WAIT.
00001 Strobe asserted 1 clock cycles
00010 Strobe asserted 2 clock cycles
...
11111 Strobe asserted 31 clock cycles
00000 Strobe asserted 32 clock cycles
25 PPS PCMCIA port size. Specifies the port size of this PCMCIA window.
0 8 bits port size
1 16 bits port size
26–28 PRS PCMCIA region select.
000 Common memory space
001 Reserved
010 Attribute memory space
011 I/O space
100 DMA (normal DMA transfer)
101 DMA last transaction
11x Reserved
Note: The DMA encoding generates a normal DMA transfer unless signaled as last by the on-chip
DMA controller. In this case TC(OE) or TC (WE) is asserted.The DMA last transaction encoding
generates a DMA transfer with TC(OE) or TC (WE) asserted, regardless of any internal indication.
29 PSLOT PCMCIA slot identifier.
0 This window defined for slot A.
1 This window defined for slot B.
30 WP Write-protect enable.
0 Not write protected.
1 Write protected. Attempting to write to this window causes a machine check interrupt.
31 PV PCMCIA valid. Indicates whether the contents of the OBR and POR pair are valid.
0 This bank is invalid.
1 This bank is valid.
Table 16-13. POR Field Descriptions (continued)
Bits Name Description