MC9328MX21CVM Freescale, MC9328MX21CVM Datasheet - Page 21

• Manufacturer Part Number: MC9328MX21CVM
• Manufacturer: Freescale

Specifications of MC9328MX21CVM

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

3.8
3.8.1
3.8.1.1
In this mode MMD_MODE_SEL bit is set and MMD_CLKOUT bit is cleared. BMI_WRITE and
BMI_CLK/CS are input signals to BMI driving by ATI MMD chip set. Output signal BMI_READ_REQ
can be used as interrupt signal to inform MMD that data is ready in BMI TxFIFO for read access. MMD
can write data to BMI RxFIFO anytime as CPU or DMA can move data out from RxFIFO much faster
than the BMI interface. Overflow interrupt is generated if RxFIFO overflow is detected. Once this
happens, the new coming data is ignored.
3.8.1.1.1
Figure 6
On each rising edge of BMI_CLK/CS BMI checks the BMI_WRITE logic level to determine if the current
cycle is a read cycle. It puts data into the data bus and enables the data out on the rising edge of BMI_CLK/
CS if BMI_WRITE is logic high. The BMI_READ_REQ is negated one hclk cycle after the BMI_CLK/
CS rising edge of last data read. The MMD cannot issues read command when BMI_READ_REQ is low
(no data in TxFIFO).
Freescale Semiconductor
t
max_req_assert
Parameter
t
t
t
min_assert
max_write
max_read
shows the MMD read BMI timing when the MMD drives clock.
BMI Interface Timing Diagram
Connecting BMI to ATI MMD Devices
ATI MMD Devices Drive the BMI_CLK/CS
Minimum assertion time of External Grant
signal
Maximum External request assertion time
after assertion of Grant signal
Maximum External request assertion time
after first read completion
Maximum External request assertion time
after completion of first write
MMD Read BMI Timing
Table 13. DMA External Request and Grant Timing Parameters
Description
MC9328MX21 Technical Data, Rev. 3.4
9 hclk - 20.66
3 hclk - 15.87
8 hclk - 6.21
8 hclk + 8.6
WCS
3.0 V
8 hclk + 2.74
8 hclk - 0.77
3 hclk - 8.83
9 hclk - 6.7
BCS
9 hclk - 17.96
8 hclk + 7.17
8 hclk - 5.84
3 hclk - 15.9
WCS
1.8 V
8 hclk + 3.25
9 hclk - 8.16
8 hclk - 0.66
3 hclk - 9.12
BCS
Specifications
Unit
ns
ns
ns
ns
21