MC7457RX1267LC Datasheet, PDF (27/71 Pages) Freescale Semiconductor, Inc – Microprocessor

Electrical and Thermal Characteristics
window at the internal receiving latches. This delayed clock is used to capture the data into these latches
which comprise the receive FIFO. This clock is asynchronous to all other processor clocks. This latched
data is subsequently read out of the FIFO synchronously to the processor clock. The time between writing
and reading the data is set by the using the sample point settings defined in the L3CR register.
Table 13 provides the L3 bus interface AC timing specifications for the configuration as shown in
Figure 9, assuming the timing relationships shown in Figure 10 and the loading shown in Figure 8.
Table 13. L3 Bus Interface AC Timing Specifications for MSUG2
At recommended operating conditions. See Table 4.
Device Revision (L3 I/O Voltage) ⁹
Parameter
Symbol
Rev 1.1. (All I/O Modes)
Rev 1.2
Rev 1.2 (1.5-V I/O Mode) (1.8-, 2.5-V I/O Modes)
Unit Notes
Min
Max
Min
Max
L3_CLK rise and fall time
t_L3CR, t_L3CF
—
0.75
—
0.75
ns
1
Setup times: Data and parity
t_L3DVEH, (– t_L3CLK/4)
—
(– t_L3CLK/4)
—
t_L3DVEL
+ 0.90
+ 0.70
ns 2, 3, 4
Input hold times: Data and parity
t_L3DXEH,
(t_L3CLK/4)
—
(t_L3CLK/4)
—
t_L3DXEL
+ 0.85
+ 0.70
ns
2, 4
Valid times: Data and parity
t_L3CHDV,
t_L3CLDV
—
(– t_L3CLK/4)
—
(– t_L3CLK/4) ns
5, 6,
+ 0.60
+ 0.50
7, 8
Valid times: All other outputs
t_L3CHOV
—
(t_L3CLK/4)
—
(t_L3CLK/4)
ns 5, 7, 8
+ 0.65
+ 0.65
Output hold times: Data and parity t_L3CHDX,
(t_L3CLK/4)
—
(t_L3CLK/4)
—
t_L3CLDX,
– 0.60
– 0.50
Output hold times: All other outputs t_L3CHOX
(t_L3CLK/4)
—
(t_L3CLK/4)
—
– 0.50
– 0.50
ns 5, 6,
7, 8
ns 5, 7, 8
L3_CLK to high impedance: Data
and parity
t_L3CLDZ
—
(– t_L3CLK/4)
—
(– t_L3CLK/4) ns
+ 0.60
+ 0.60
MPC7457 RISC Microprocessor Hardware Specifications, Rev. 8
Freescale Semiconductor
27