ꢀ ꢁ ꢂ ꢃ ꢄꢅ ꢆ ꢇ ꢈꢉ ꢈꢀꢊ ꢀꢁ ꢂꢃ ꢄ ꢅ ꢆꢇ ꢈ ꢉ ꢋꢀꢊ ꢀꢁ ꢂꢃ ꢄ ꢅ ꢆꢇ ꢈ ꢉ ꢇ ꢀ
ꢌ ꢍ ꢎꢏ ꢐꢑꢒ ꢓꢍ ꢔ ꢀ ꢐꢍ ꢕ ꢍ ꢀꢖꢗ ꢂ ꢍ ꢕꢔ ꢖꢗ ꢒ ꢘꢓ ꢆꢏ ꢂꢂꢓ ꢘꢂ
SPRS226H − NOVEMBER 2003 − REVISED AUGUST 2005
HOLD/HOLDA TIMING
†
timing requirements for the HOLD/HOLDA cycles for EMIFA and EMIFB modules (see Figure 35)
−600, −720
−850, −1G
NO.
UNIT
MIN MAX
3
t
Hold time, HOLD low after HOLDA low
E
ns
h(HOLDAL-HOLDL)
†
E = the EMIF input clock (ECLKIN, CPU/4 clock, or CPU/6 clock) period in ns for EMIFA or EMIFB.
switching characteristics over recommended operating conditions for the HOLD/HOLDA cycles
†‡§
for EMIFA and EMIFB modules
(see Figure 35)
−600, −720
−850, −1G
NO.
PARAMETER
UNIT
MIN
2E
0
MAX
¶
1
2
4
5
6
7
t
t
t
t
t
t
Delay time, HOLD low to EMIF Bus high impedance
Delay time, EMIF Bus high impedance to HOLDA low
Delay time, HOLD high to EMIF Bus low impedance
Delay time, EMIF Bus low impedance to HOLDA high
Delay time, HOLD low to ECLKOUTx high impedance
Delay time, HOLD high to ECLKOUTx low impedance
ns
ns
ns
ns
ns
ns
d(HOLDL-EMHZ)
d(EMHZ-HOLDAL)
d(HOLDH-EMLZ)
d(EMLZ-HOLDAH)
d(HOLDL-EKOHZ)
d(HOLDH-EKOLZ)
2E
7E
2E
0
2E
¶
2E
2E
7E
†
‡
E = the EMIF input clock (ECLKIN, CPU/4 clock, or CPU/6 clock) period in ns for EMIFA or EMIFB.
For EMIFA, EMIF Bus consists of: ACE[3:0], ABE[7:0], AED[63:0], AEA[22:3], AARE/ASDCAS/ASADS/ASRE, AAOE/ASDRAS/ASOE, and
AAWE/ASDWE/ASWE , ASDCKE, ASOE3, and APDT.
For EMIFB, EMIF Bus consists of: BCE[3:0], BBE[1:0], BED[15:0], BEA[20:1], BARE/BSDCAS/BSADS/BSRE, BAOE/BSDRAS/BSOE, and
BAWE/BSDWE/BSWE, BSOE3, and BPDT.
The EKxHZ bits in the EMIF Global Control register (GBLCTL) determine the state of the ECLKOUTx signals during HOLDA. If EKxHZ = 0,
ECLKOUTx continues clocking during Hold mode. If EKxHZ = 1, ECLKOUTx goes to high impedance during Hold mode, as shown in Figure 35.
All pending EMIF transactions are allowed to complete before HOLDA is asserted. If no bus transactions are occurring, then the minimum delay
time can be achieved. Also, bus hold can be indefinitely delayed by setting NOHOLD = 1.
§
¶
External Requestor
DSP Owns Bus
DSP Owns Bus
Owns Bus
3
HOLD
2
5
HOLDA
1
4
7
†
EMIF Bus
C64x
C64x
‡
ECLKOUTx
(EKxHZ = 0)
6
‡
ECLKOUTx
(EKxHZ = 1)
†
‡
For EMIFA, EMIF Bus consists of: ACE[3:0], ABE[7:0], AED[63:0], AEA[22:3], AARE/ASDCAS/ASADS/ASRE, AAOE/ASDRAS/ASOE, and
AAWE/ASDWE/ASWE, ASDCKE, ASOE3, and APDT.
For EMIFB, EMIF Bus consists of: BCE[3:0], BBE[1:0], BED[15:0], BEA[20:1], BARE/BSDCAS/BSADS/BSRE, BAOE/BSDRAS/BSOE, and
BAWE/BSDWE/BSWE, BSOE3, and BPDT.
The EKxHZ bits in the EMIF Global Control register (GBLCTL) determine the state of the ECLKOUTx signals during HOLDA. If EKxHZ = 0,
ECLKOUTx continues clocking during Hold mode. If EKxHZ = 1, ECLKOUTx goes to high impedance during Hold mode, as shown in Figure 35.
Figure 35. HOLD/HOLDA Timing for EMIFA and EMIFB
104
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
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