
TMS320C6203B, TMS320C6203C
FIXEDPOINT DIGITAL SIGNAL PROCESSORS
SPRS086G – JANUARY 1999 – REVISED JANUARY 2002
69
POST OFFICE BOX 1443
HOUSTON, TEXAS 77251–1443
EXPANSION BUS ASYNCHRONOUS PERIPHERAL TIMING
timing requirements for asynchronous peripheral cycles§ (see Figure 33–Figure 36)
NO.
C6203B-250
C6203B-300
C6203C-300
UNIT
NO.
MIN
MAX
MIN
MAX
UNIT
3
tsu(XDV-XREH)
Setup time, XDx valid before XRE
high
4.5
3
ns
4
th(XREH-XDV)
Hold time, XDx valid after XRE high
2.5
1
ns
6
tsu(XRDYH-XREL)
Setup time, XRDY high before XRE
low
–[(RST – 3) * P – 6]
ns
7
th(XREL-XRDYH)
Hold time, XRDY high after XRE low
(RST – 3) * P + 2
ns
9
tsu(XRDYL-XREL)
Setup time, XRDY low before XRE
low
–[(RST – 3) * P – 6]
ns
10
th(XREL-XRDYL)
Hold time, XRDY low after XRE low
(RST – 3) * P + 2
ns
11
tw(XRDYH)
Pulse width, XRDY high
2P
ns
15
tsu(XRDYH-XWEL)
Setup time, XRDY high before XWE
low
–[(WST – 3) * P – 6]
ns
16
th(XWEL-XRDYH)
Hold time, XRDY high after XWE
low
(WST – 3) * P + 2
ns
18
tsu(XRDYL-XWEL)
Setup time, XRDY low before XWE
low
–[(WST – 3) * P – 6]
ns
19
th(XWEL-XRDYL)
Hold time, XRDY low after XWE low
(WST – 3) * P + 2
ns
To ensure data setup time, simply program the strobe width wide enough. XRDY is internally synchronized. If XRDY does meet setup or hold
time, it may be recognized in the current cycle or the next cycle. Thus, XRDY can be an asynchronous input.
RS = Read Setup, RST = Read Strobe, RH = Read Hold, WS = Write Setup, WST = Write Strobe, WH = Write Hold. These parameters are
programmed via the XBUS XCE space control registers.
§ P = 1/CPU clock frequency in ns. For example, when running parts at 300 MHz, use P = 3.3 ns.
The sum of RS and RST (or WS and WST) must be a minimum of 4 in order to use XRDY input to extend strobe width.
PRODUCT
PREVIEW