
i.MX51 Applications Processors for Consumer and Industrial Products, Rev. 4
56
Freescale Semiconductor
Electrical Characteristics
WE5
Clock rise to address
invalid
0.5t-1.25
—
t-1.25
t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE6
Clock rise to CSx_B valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE7
Clock rise to CSx_B
invalid
0.5t-1.25
0.5t+1.75
2t-1.25
2t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE8
Clock rise to WE_B Valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE9
Clock rise to WE_B
Invalid
0.5t-1.25
0.5t+1.75
2t-1.25
2t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE10
Clock rise to OE_B Valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE11
Clock rise to OE_B
Invalid
0.5t-1.25
0.5t+1.75
2t-1.25
2t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE12
Clock rise to BEy_B Valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE13
Clock rise to BEy_B
Invalid
0.5t-1.25
0.5t+1.75
t-1.25
t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE14
Clock rise to ADV_B
Valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE15
Clock rise to ADV_B
Invalid
0.5t-1.25
0.5t+1.75
t-1.25
t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE164 Clock rise to Output Data
Valid
-0.5t-1.25
-0.5t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
-t-1.25
-t+1.75
WE174 Clock rise to Output Data
Invalid
0.5t-1.25
0.5t+1.75
t-1.25
t+1.75
2t-1.25
2t+1.75
3t-1.25
3t+1.75
WE184 Input Data setup time to
Clock rise
2
—
4
—
———
—
WE194 Input Data hold time from
Clock rise
2
—
2
—
———
—
WE20
WAIT_B setup time to
Clock rise
2
—
4
—
———
—
WE21
WAIT_B hold time from
Clock rise
2
—
2
—
———
—
1 t is axi_clk cycle time. The maximum allowed axi_clk frequency is 133 MHz, whereas the maximum allowed BCLK frequency
is 104 MHz. As a result if BCD = 0, axi_clk must be
≤104 MHz. If BCD = 1, then 133 MHz is allowed for axi_clk, resulting in a
BCLK of 66.5 MHz. When the clock branch to WEIM is decreased to 104 MHz, other busses are impacted which are clocked
from this source. See the CCM chapter of the i.MX51 Multimedia Applications Processor Reference Manual (MCIMX51RM)
for a detailed clock tree description.
2 BCLK parameters are being measured from the 50% point that is, high is defined as 50% of signal value and low is defined
as 50% as signal value.
3 For signal measurements “High” is defined as 80% of signal value and “Low” is defined as 20% of signal value.
4 The lower 16 bits of the WEIM bus are limited to 90 MHz.”
Table 53. WEIM Bus Timing Parameters (continued)1
ID
Parameter
BCD = 0
BCD = 1
BCD = 2
BCD = 3
Min
Max
Min
Max
Min
Max
Min
Max