XA-S3 NXP Semiconductors, XA-S3 Datasheet - Page 42

no-image

XA-S3

Manufacturer Part Number
XA-S3
Description
The XA-S3 device is a member of Philips Semiconductors? XA(eXtended Architecture) family of high performance 16-bitsingle-chip microcontrollers
Manufacturer
NXP Semiconductors
Datasheet
3. Not all combinations of bus timing configuration values result in valid bus cycles. Please refer to the XA User Guide section on the External
4. When code is being fetched for execution on the external bus, a burst mode fetch is used that dows not have PSEN edges in every fetch
5. This parameter is provided for peripherals that have the data clocked in on the falling edge of the WR strobe. This is not usually the case
6. Please note that the XA-S3 requires that extended data bus hold time (WM0 = 1) to be used with external bus write cycles.
7. Applies only to an external clock source, not when a crystal is connected to the XTAL1 and XTAL2 pins.
8. WAIT should not change between these times.
Philips Semiconductors
2000 Dec 01
V11)
XA 16-bit microcontroller
32 K/1 K OTP/ROM/ROMless, 8-channel 8-bit A/D, low voltage (2.7 V–5.5 V),
I
V7)
V8)
V9)
V10) This variable represents the length of a bus strobe for calculation of WAIT set-up and hold times. The strobe may be RD (for data
V12) this variable represents the programmed period between the end of the ALE pulse and the beginning of the WRL and/or WRH pulse
V13) This variable represents the programmed data setup time for a write as determined by the data write cycle duration (defined by DW1
Bus for details.
cycle. This would be A3–A0 for an 8-bit bus, and A3–A1 for a 16-bit bus. Also, a 16-bit read operation conducted on an 8-bit wide bus
similarly does not include two separate RD strobes. So, a rising edge on the low order address line (A0) must be used to trigger a WAIT in
the second half of such a cycle.
and in most applications this parameter is not used.
2
C, 2 UARTs, 16 MB address range
register, and the values of V1 and V8. V12 = the total bus cycle duration (2 if DWA1/0 = 00, 3 if DWA1/0 = 01, 4 if DWA1/0 = 10, and 5
BTRH register, and the SLEW bit in the BTRL register. Note that during a 16-bit operation on an 8-bit external bus, RD remains low
and does not exhibit a transition between the first and second byte bus cycles. V7 still applies for the purpose of determining
peripheral timing requirements. The timing for the first byte is for a bus cycle with ALE, the timing for the second byte is for a bus
cycle with no ALE.
– For a bus cycle with no ALE, V7 = 1 if DR1/0 = 00, 2 if DR1/0 = 01, 3 if DR1/0 = 10, and 4 if DR1/0 = 11.
– For a bus cycle with an ALE, V7 = the total bus cycle duration (2 if DRA1/0 = 00, 3 if DRA1/0 = 01, 4 if DRA1/0 = 10, and
V8 = 1 if WM1 = 0, and 2 if WM1 = 1.
DW1 and DW0 or the DWA1 and DWA0 bits in the BTRH register), the WM0 bit in the BTRL register, and the value of V8.
– For a bus cycle with an ALE, V9 = the total bus write cycle duration (2 if DWA1/0 = 00, 3 if DWA1/0 = 01, 4 if DWA1/0 = 10, and
– For a bus cycle with no ALE, V9 = the total bus cycle duration (2 if DW1/0 = 00, 3 if DW1/0 = 01, 4 if DW1/0 = 10, and
read cycles), WRL and/or WRH (for data write cycles), or PSEN (for code read cycles), depending on the type of bus cycle being
widened by WAIT. V10 = 2 for WAIT associated with a code read cycle using PSEN. V10 = V8 for a data write cycle using WRL
and/or WRH. V10 = V7 – 1 for a data read cycle using RD. This means that a single clock data read cycle cannot be stretched using
WAIT. If WAIT is used to vary the duration of data read cycles, the RD strobe width must be set to be at least two clocks in duration.
Also see Note 4.
This variable represents the programmed write hold time as determined by the WM0 bit in the BTRL register. V11 0 if the WM0 bit = 0,
and 1 if the WM0 bit = 1.
as determined by the data write cycle duration (defined by the DWA1 and DWA0 bits in the BTRH register), the WM0 bit in the BTRL
if DWA1/0 = 11) minus the number of clocks used by the WRL and/or WRH pulse (V8), minus the number of clocks used by data hold
time (0 if WM0 = 0 and 1 if WM0 = 1), minus the width of the ALE pulse (V1).
Example: If SWA1/0 = 11, WM0 = 1, WM1 = 0, and ALEW = 1, then V12 = 5 – 1 – 1 – 1.5 = 1.5.
and DW0 or the DWA1 and DWA0 bits in the BTRH register), the WM0 bit in the BTRL register, and the values of V1 and V8.
– For a bus cycle with an ALE, V13 = the total bus cycle duration (2 if DWA1/0 = 00, 3 if DWA1/0 = 01, 4 if DWA1/0 = 10, and
– For a bus cycle with no ALE, V13 = the total bus cycle duration (2 if DW1/0 = 00, 3 if DW1/0 = 01, 4 if DW1/0 = 10, and
This variable represents the programmed width of the RD pulse as determined by the DR1 and DR0 bits or the DRA1, DRA0 in the
This variable represents the programmed width of the WRL and/or WRH pulse as determined by the WM1 bit in the BTRL register.
This variable represents the programmed address setup time for a write as determined by the data write cycle duration (defined by
5 if DRA1/0 = 11) minus the number of clocks used by ALE (V1 + 0.5).
Example: if DRA1/0 = 00 and ALEW = 0, then V7 = 2 – (0.5 +0.5) = 1.
5 if DWA1/0 = 11) minus the number of clocks used by the WRL and/or WRH pulse (V8) minus the number of clocks used by data
hold time (0 if WM0 = 0 and 1 if WM0 = 1).
Example: If DWA1/0 = 10, WM0 = 1, and WM1 = 1, then V9 = 4 – 1 – 2 = 1.
5 if DW1/0 = 11) minus the number of clocks used by the WRL and/or WRH pulse (V8), minus the number of clocks used by data
hold time (0 if WMo = 0 and 1 if WM0 = 1).
Example: If DW1/0 = 11, WM0 = 1, and WM1 = 0, then V9 = 5 – 1 – 1 = 3.
5 if DWA1/0 = 11) minus the number of clocks used by the WRL and/or WRH pulse (V8), minus the number of clocks used by
data hold time (0 if WM0 = 0 and 1 if WM0 = 1), minus the number of clocks used by ALE (V1 + 0.5).
Example: If DWA1/0 = 11, WM0 = 1, WM1 = 1, and ALEW = 0, then V13 = 5 – 1 – 2 – 1 = 1.
5 if DW1/0 = 11) minus the number of clocks used by the WRL and/or WRH pulse (V8), minus the number of clocks used by
data hold time (0 if WM0 = 0 and 1 if WM0 = 1).
Example: If DW1/0 = 01, WM0 = 1, and WM1 = 0, then V13 = 3 – 1 – 1 = 1.
42
Preliminary specification
XA-S3

Related parts for XA-S3