
IBM PowerPC 403GC
27
Notes:
1. For normal RAS and CAS timing, TOH is relative to the rising edge of SysClk and TOV is relative to the falling edge
of SysClk. In early RAS mode, TOV is relative to the rising edge of SysClk. CAS access time assumes a SysClk
50% duty cycle.
2. In early RAS mode, the RAS output delay varies with the 403GC operating frequency. Use the following equation
to determine the worst-case output delay for this signal: TOVMax = 12 ns + Tc/4; TOHMin remains unchanged.
Valid for Tc greater than 30 ns and less than 80 ns.
3. When initiating a system reset, the 403GC pulls the Reset output low for 2048 cycles minimum and then samples
to determine whether Reset is held low externally. Thirty-two cycles after Reset has been sampled as low, the
403GCbegins its internal reset.
4. Output times are measured with a standard 50 pF capacitive load, unless otherwise noted. Output hold times are
measured at 3.47V and TJ = 10°C.
5. All output hold and float times are guaranteed by design and not tested.
Table 17. 403GC Synchronous Output Timings
Symbol
Parameter
25 MHz
33 MHz
40 MHz
Units
TOHMin TOVMax TOHMin TOVMax TOHMin TOVMax
TOH, TOV Output hold, output valid time
TOH1, TOV1 A6:31
TOH2, TOV2 AMuxCAS
TOH3, TOV3 BusReq
TOH4, TOV4 CAS0:3
TOH5, TOV5 CS0:7
TOH6, TOV6 D0:31
TOH7, TOV7 DMAA0:3
TOH8, TOV8 DMADXFER
TOH9, TOV9 DRAMOE
TOH10, TOV10 DRAMWE
TOH11, TOV11 Error
TOH12, TOV12 HoldAck
TOH13, TOV13 OE
TOH14, TOV14 RAS0:3
TOH15, TOV15 RAS0:3 (Early)
TOH16, TOV16 Reset
TOH17, TOV17 R/W
TOH18, TOV18 TC0:3
TOH19, TOV19 TS0:6
TOH20, TOV20 WBE0:3(BE0:3)
TOH21, TOV21 XAck
4
3
4
2
4
3
2
4
3
12
3
4
3
15
11
12
13
16
11
13
11
10
14
12
11
12
22
14
11
13
30
12
13
4
3
4
2
4
3
4
3
11
3
4
3
13
11
12
11
15
10
11
10
12
11
10
11
20
12
10
12
25
11
12
4
3
4
2
4
3
4
3
11
3
4
3
11
10
11
10
14
9
10
9
12
10
9
10
18
12
9
11
22
10
11
ns
TOF
Output float time
TOF1 A6:31
TOF2 CS0:7
TOF3 D0:31
TOF4 OE
TOF5 Reset
TOF6 R/W
TOF7 TC0:3
TOF8 WBE0:3(BE0:3)
Min
2
3
2
3
Max
10
12
11
12
8
12
Min
2
3
2
3
Max
9
10
9
10
7
10
Min
2
3
2
3
Max
9
10
9
10
7
10
ns
TCAS
Available CAS access time
Min
Max
Min
Max
Min
Max
ns
2-1-1-1 access mode (Note )
3-2-2-2 access mode (Note )
0.5TC -2.5
1.5TC -2.5
0.5TC - 2.5
1.5TC -2.5
0.5TC - 2.5
1.5TC -2.5