mcf5307cft90b Freescale Semiconductor, Inc, mcf5307cft90b Datasheet - Page 378

• Manufacturer Part Number: mcf5307cft90b
• Description: Mcf5307 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Clock and Reset Signals
17.5.5.1 D[7:5Boot Chip-Select (CS0) Configuration
D[7:5] determine defaults for the global chip select (CS0), the only chip select valid at reset.
These signals correspond to bits in chip-select configuration register 0 (CSCR0).
17.5.5.2 D7—Auto Acknowledge Configuration (AA_CONFIG)
At reset, the enabling and disabling of auto acknowledge for boot CS0 is determined by the
logic level driven on D7 at the rising edge of RSTI. AA_CONFIG is multiplexed with D7
and sampled only at reset. The D7 logic level is reflected as the reset value of CSCR[AA].
Table 17-12 shows how the D7 logic level corresponds to the auto acknowledge timing for
CS0 at reset. Note that auto acknowledge can be disabled by driving a logic 0 on D7 at reset.
17.5.5.3 D[6:5]—Port Size Configuration (PS_CONFIG[1:0])
The default port size value of the boot CS0 is determined by the logic levels driven on
D[6:5] at the rising edge of RSTI, which are reflected as the reset value of CSCR[PS]. Table
17-13 shows how the logic levels of D[6:5] correspond to the CS0 port size at reset.
17.5.6 D4—Address Configuration (ADDR_CONFIG)
The address configuration signal (ADDR_CONFIG) programs the PAR of the parallel I/O
port to be either parallel I/O or to be the upper address bus bits along with various attribute
and control signals at reset to give the user the option to access a broader addressing range
17-14
Table 17-12. D7 Selection of CS0 Automatic Acknowledge
Table 17-13. D6 and D5 Selection of CS0 Port Size
D[6:5]
D[3:2]
D[1:0]
Pin
D7
D4
D7 (CSCR0[AA])
Freescale Semiconductor, Inc.
Auto-acknowledge configuration (AA_CONFIG)
Port size configuration (PS_CONFIG[1:0])
Address configuration (ADDR_CONFIG/D4)
Frequency Control PLL (FREQ[1:0])
Divide Control (DIVIDE[1:0])
Table 17-11. Data Pin Configuration
For More Information On This Product,
D[6:5] (CSCR0[PS])
0
1
00
01
1x
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MCF5307 User’s Manual
Disabled
Enabled with 15 wait states
Function
Boot CS0 Port Size
Boot CS0 AA
32-bit port
16-bit port
8-bit port