MC9328MXL Datasheet, PDF (60/84 Pages) Freescale Semiconductor, Inc – i.MX Integrated Portable System Processor

Specifications
3.14 Pulse-Width Modulator
The PWM can be programmed to select one of two clock signals as its source frequency. The selected
clock signal is passed through a divider and a prescaler before being input to the counter. The output is
available at the pulse-width modulator output (PWMO) external pin. Its timing diagram is shown in
Figure 47 and the parameters are listed in Table 22.
System Clock
PWM Output
2a
2b
4a
1
3b
3a
4b
Figure 47. PWM Output Timing Diagram
Table 22. PWM Output Timing Parameter Table
Ref
No.
Parameter
1
System CLK frequency¹
2a Clock high time¹
2b Clock low time¹
3a Clock fall time¹
3b Clock rise time¹
4a Output delay time¹
4b Output setup time¹
1. C_L of PWMO = 30 pF
1.8V ± 0.10V
Minimum
Maximum
0
87
3.3
–
7.5
–
–
5
–
6.67
5.7
–
5.7
–
3.0V ± 0.30V
Minimum
Maximum
0
100
5/10
–
5/10
–
–
5/10
–
5/10
5
–
5
–
Unit
MHz
ns
ns
ns
ns
ns
ns
3.15 SDRAM Controller
A write to an address within the memory region initiates the program sequence. The first command issued
to the SyncFlash is Load Command Register. The value in A [7:0] determines which operation the
command performs. For this write setup operation, an address of 0x40 is hardware generated. The bank
and other address lines are driven with the address to be programmed. The next command is Active which
registers the row address and confirms the bank address. The third command supplies the column address,
re-confirms the bank address, and supplies the data to be written. SyncFlash does not support burst writes,
therefore a Burst Terminate command is not required.
A read to the memory region initiates the status read sequence. The first command issued to the SyncFlash
is the Load Command Register with A [7:0] set to 0x70 which corresponds to the Read Status Register
operation. The bank and other address lines are driven to the selected address. The second command is
MC9328MXL Advance Information, Rev. 5
60
Freescale Semiconductor