SCN68562 Datasheet, PDF (9/18 Pages) NXP Semiconductors – Dual universal serial communications controller DUSCC

Philips Semiconductors
Dual universal serial communications controller (DUSCC)
Product specification
SCN68562
NO.
FIGURE
PARAMETER
LIMITS
Min
Typ
Max
UNIT
42
16
CSN Low to transmit DMA REQ negated
400
nS
43
16
CSN Low to receive DONEN Low
300
nS
44
16
CSN Low to receive DMA REQ negated
400
nS
NOTES:
1. Parameters are valid over specified temperature range.
2. All voltage measurements are referenced to ground (GND). For DC and functional testing, all inputs except X1/CLK swing between 0.8V and
2.0V with a transition time of 20ns maximum. For X1/CLK, this swing is between 0.4V and 2.4V All time measurements are referenced at
input voltages of 0.4V and 2.4V for all inputs. Output levels are referenced at 1.2V and 2.0V, as appropriate.
3. Test conditions for outputs: C_L = 150pF, except open-drain outputs. Test condition for open-drain outputs: C_L = 50pF to GND, R_L = 2.7kΩ to V_CC
except DTACKN whose R_L = 820Ω to V_CC and C_L = 150pF to GND and DONEN which requires C_L = 50pF to GND and R_L = 1kΩ to V_CC.
4. This specification will impose maximum 68000 CPU CLK to 6MHz. Higher CPU CLK can be used if repeating bus cycles are not performed.
5. Execution of the valid command (after it is latched) requires three falling edges of X1 (see Figure 14).
6. In single address DMA mode write operation, data is latched by the falling edge of DTCN.
7. These values were not explicitly tested, they are guaranteed by design and characterization data.
8. These timings are from the falling edge of DTACKN (not CSN rising).
9. X1/CLK frequency must be at least four times the receiver serial data rate.
RESETN
A1–A6
R/WN
CSN
D0–D7
DTACKN
X1/CLK
1
SD00224
Figure 3. Reset Timing
2
3
4
5
6
8
9
11
7
13
12
Figure 4. Bus Timing (Read Cycle)
14
SD00225
DTACKN
COMMAND
VALID
1995 May 01
Figure 5. Command Timing
9
SD00226