PHILIPS PXAG37KFA

INTEGRATED CIRCUITS
XA-G37
XA 16-bit microcontroller family
32K OTP, 512 B RAM, watchdog, 2 UARTs
Product data
Replaces datasheet XA-G3 of 2001 Jun 25
2002 Mar 25
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
FAMILY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIFIC FEATURES OF THE XA-G37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PIN CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44-Pin PLCC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44-Pin LQFP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOGIC SYMBOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PIN DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL FUNCTION REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
XA-G37 TIMER/COUNTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timer 0 and Timer 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Enhanced Mode 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Timer-Overflow Toggle Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timer T2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capture Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto-Reload Mode (Up or Down Counter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Baud Rate Generator Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programmable Clock-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WATCHDOG TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Watchdog Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Watchdog Control Register (WDCON) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Watchdog Detailed Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WDCON Register Bit Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Serial Port Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TI Flag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-bit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bypassing Double Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note Regarding Older XA-G37 Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CLOCKING SCHEME/BAUD RATE GENERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Timer 2 to Generate Baud Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prescaler Select for Timer Clock (TCLK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UART INTERRUPT SCHEME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Error Handling, Status Flags and Break Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiprocessor Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Address Recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O PORT OUTPUT CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EXTERNAL BUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RESET OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
POWER REDUCTION MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC ELECTRICAL CHARACTERISTICS (VDD = 4.5 V TO 5.5 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC ELECTRICAL CHARACTERISTICS (VDD = 2.7 V TO 4.5 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EPROM CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2002 Mar 25
i
1
1
1
2
2
2
2
3
4
5
8
8
9
9
9
9
10
10
10
10
11
11
13
13
13
13
14
14
15
15
15
15
15
16
16
16
17
17
17
17
19
19
19
19
19
20
21
21
22
22
23
31
31
34
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
• Instruction set tailored for high level language support
• Multi-tasking and real-time executives that include up to 32
FAMILY DESCRIPTION
The Philips Semiconductors XA (eXtended Architecture) family of
16-bit single-chip microcontrollers is powerful enough to easily
handle the requirements of high performance embedded
applications, yet inexpensive enough to compete in the market for
high-volume, low-cost applications.
vectored interrupts, 16 software traps, segmented data memory,
and banked registers to support context switching
• Low power operation, which is intrinsic to the XA architecture,
includes power-down and idle modes.
The XA family provides an upward compatibility path for 80C51
users who need higher performance and 64k or more of program
memory. Existing 80C51 code can also easily be translated to run
on XA microcontrollers.
More detailed information on the core is available in the XA User
Guide.
The performance of the XA architecture supports the
comprehensive bit-oriented operations of the 80C51 while
incorporating support for multi-tasking operating systems and
high-level languages such as C. The speed of the XA architecture,
at 10 to 100 times that of the 80C51, gives designers an easy path
to truly high performance embedded control.
SPECIFIC FEATURES OF THE XA-G37
• 20-bit address range, 1 megabyte each program and data space.
(Note that the XA architecture supports up to 24 bit addresses.)
• 2.7 V to 5.5 V operation
• 32K bytes on-chip EPROM program memory
• 512 bytes of on-chip data RAM
• Three counter/timers with enhanced features
The XA architecture supports:
• Upward compatibility with the 80C51 architecture
• 16-bit fully static CPU with a 24-bit program and data address
range
(equivalent to 80C51 T0, T1, and T2)
• Eight 16-bit CPU registers each capable of performing all
• Watchdog timer
• Two enhanced UARTs
• Four 8-bit I/O ports with 4 programmable output configurations
• 44-pin PLCC and 44-pin LQFP packages
arithmetic and logic operations as well as acting as memory
pointers. Operations may also be performed directly to memory.
• Both 8-bit and 16-bit CPU registers, each capable of performing
all arithmetic and logic operations.
• An enhanced instruction set that includes bit intensive logic
operations and fast signed or unsigned 16 × 16 multiply and
32 / 16 divide
ORDERING INFORMATION
Package
Type number
Name
Description
Temperature
Range (°C)
Version
LQFP44
PXAG37KBBD
OTP1
plastic low profile quad flat package; 44 leads; body 10 × 10 × 1.4 mm
0 to +70
SOT389-1
PXAG37KBA
OTP1 PLCC44
plastic leaded chip carrier; 44 leads
0 to +70
SOT187-2
PXAG37KFBD
OTP1
plastic low profile quad flat package; 44 leads; body 10 × 10 × 1.4 mm
–40 to +85
SOT389-1
PXAG37KFA
OTP1 PLCC44
plastic leaded chip carrier; 44 leads
–40 to +85
SOT187-2
LQFP44
NOTE:
1. OTP = One Time Programmable EPROM.
2002 Mar 25
1
853-2325 27917
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
PIN CONFIGURATIONS
44-Pin PLCC Package
6
44-Pin LQFP Package
1
44
40
7
34
39
1
33
PLCC
LQFP
17
18
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
11
29
23
28
Pin
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Function
VSS
P1.0/A0/WRH
P1.1/A1
P1.2/A2
P1.3/A3
P1.4/RxD1
P1.5/TxD1
P1.6/T2
P1.7/T2EX
RST
P3.0/RxD0
NC
P3.1/TxD0
P3.2/INT0
P3.3/INT1
P3.4/T0
P3.5/T1/BUSW
P3.6/WRL
P3.7/RD
XTAL2
XTAL1
VSS
12
Function
VDD
P2.0/A12D8
P2.1/A13D9
P2.2/A14D10
P2.3/A15D11
P2.4/A16D12
P2.5/A17D13
P2.6/A18D14
P2.7/A19D15
PSEN
ALE/PROG
NC
EA/VPP/WAIT
P0.7/A11D7
P0.6/A10D6
P0.5/A9D5
P0.4/A8D4
P0.3/A7D3
P0.2/A6D2
P0.1/A5D1
P0.0/A4D0
VDD
SU00525
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
22
Pin
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Function
P1.5/TxD1
P1.6/T2
P1.7/T2EX
RST
P3.0/RxD0
NC
P3.1/TxD0
P3.2/INT0
P3.3/INT1
P3.4/T0
P3.5/T1/BUSW
P3.6/WRL
P3.7/RD
XTAL2
XTAL1
VSS
VDD
P2.0/A12D8
P2.1/A13D9
P2.2/A14D10
P2.3/A15D11
P2.4/A16/D12
LOGIC SYMBOL
VDD
VSS
XTAL1
XTAL2
RXD1
A3
A2
A1
A0/WRH
ADDRESS
BUS
PORT 1
T2EX*
T2*
TXD1
RST
EA/WAIT
*
PORT 0
RxD0
TxD0
INT0
INT1
T0
T1/BUSW
WRL
RD
PORT 3
ALTERNATE FUNCTIONS
ALE
NOT AVAILABLE ON 40-PIN DIP PACKAGE
2002 Mar 25
ADDRESS AND DATA BUS
PORT 2
PSEN
SU00526
2
Function
P2.5/A17D13
P2.6/A18D14
P2.7/A19D15
PSEN
ALE/PROG
NC
EA/VPP/WAIT
P0.7/A11D7
P0.6/A10D6
P0.5/A9D5
P0.4/A8D4
P0.3/A7D3
P0.2/A6D2
P0.1/A5D1
P0.0/A4D0
VDD
VSS
P1.0/A0/WRH
P1.1/A1
P1.2/A2
P1.3/A3
P1.4/RxD1
SU00580
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
BLOCK DIAGRAM
XA CPU Core
Program
Memory
Bus
SFR BUS
32 KBYTES
EPROM
UART0
512 BYTES
STATIC RAM
Data Bus
UART1
PORT 0
TIMER 0 &
TIMER 1
PORT 1
TIMER 2
PORT 2
WATCHDOG
TIMER
PORT 3
SU01632
2002 Mar 25
3
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
PIN DESCRIPTIONS
PIN. NO.
MNEMONIC
TYPE
NAME AND FUNCTION
PLCC
LQFP
VSS
1, 22
16
I
Ground: 0 V reference.
VDD
23, 44
17
I
Power Supply: This is the power supply voltage for normal, idle, and power down operation.
P0.0 – P0.7
43–36
37–30
I/O
Port 0: Port 0 is an 8-bit I/O port with a user-configurable output type. Port 0 latches have 1s
written to them and are configured in the quasi-bidirectional mode during reset. The operation of
port 0 pins as inputs and outputs depends upon the port configuration selected. Each port pin is
configured independently. Refer to the section on I/O port configuration and the DC Electrical
Characteristics for details.
When the external program/data bus is used, Port 0 becomes the multiplexed low data/instruction
byte and address lines 4 through 11.
P1.0 – P1.7
P2.0 – P2.7
2–9
40–44,
1–3
I/O
2
40
O
3
4
5
6
7
8
9
41
42
43
44
1
2
3
O
O
O
I
O
I/O
I
24–31
18–25
I/O
Port 1: Port 1 is an 8-bit I/O port with a user-configurable output type. Port 1 latches have 1s
written to them and are configured in the quasi-bidirectional mode during reset. The operation of
port 1 pins as inputs and outputs depends upon the port configuration selected. Each port pin is
configured independently. Refer to the section on I/O port configuration and the DC Electrical
Characteristics for details.
Port 1 also provides special functions as described below.
A0/WRH:
Address bit 0 of the external address bus when the external data bus is
configured for an 8 bit width. When the external data bus is configured for a 16
bit width, this pin becomes the high byte write strobe.
A1:
Address bit 1 of the external address bus.
A2:
Address bit 2 of the external address bus.
A3:
Address bit 3 of the external address bus.
RxD1 (P1.4):
Receiver input for serial port 1.
TxD1 (P1.5):
Transmitter output for serial port 1.
T2 (P1.6):
Timer/counter 2 external count input/clockout.
T2EX (P1.7):
Timer/counter 2 reload/capture/direction control
Port 2: Port 2 is an 8-bit I/O port with a user-configurable output type. Port 2 latches have 1s
written to them and are configured in the quasi-bidirectional mode during reset. The operation of
port 2 pins as inputs and outputs depends upon the port configuration selected. Each port pin is
configured independently. Refer to the section on I/O port configuration and the DC Electrical
Characteristics for details.
When the external program/data bus is used in 16-bit mode, Port 2 becomes the multiplexed high
data/instruction byte and address lines 12 through 19. When the external program/data bus is used in
8-bit mode, the number of address lines that appear on port 2 is user programmable.
P3.0 – P3.7
11,
13–19
5,
7–13
I/O
11
13
14
15
16
17
5
7
8
9
10
11
I
O
I
I
I/O
I/O
18
19
12
13
O
O
RST
10
4
I
ALE/PROG
33
27
I/O
2002 Mar 25
Port 3: Port 3 is an 8-bit I/O port with a user configurable output type. Port 3 latches have 1s
written to them and are configured in the quasi-bidirectional mode during reset. the operation of
port 3 pins as inputs and outputs depends upon the port configuration selected. Each port pin is
configured independently. Refer to the section on I/O port configuration and the DC Electrical
Characteristics for details.
Port 3 also provides various special functions as described below.
RxD0 (P3.0):
Receiver input for serial port 0.
TxD0 (P3.1):
Transmitter output for serial port 0.
INT0 (P3.2):
External interrupt 0 input.
INT1 (P3.3):
External interrupt 1 input.
T0 (P3.4):
Timer 0 external input, or timer 0 overflow output.
T1/BUSW (P3.5): Timer 1 external input, or timer 1 overflow output. The value on this pin is
latched as the external reset input is released and defines the default
external data bus width (BUSW). 0 = 8-bit bus and 1 = 16-bit bus.
WRL (P3.6):
External data memory low byte write strobe.
RD (P3.7):
External data memory read strobe.
Reset: A low on this pin resets the microcontroller, causing I/O ports and peripherals to take on
their default states, and the processor to begin execution at the address contained in the reset
vector. Refer to the section on Reset for details.
Address Latch Enable/Program Pulse: A high output on the ALE pin signals external circuitry to
latch the address portion of the multiplexed address/data bus. A pulse on ALE occurs only when it
is needed in order to process a bus cycle.
4
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
PIN. NO.
MNEMONIC
TYPE
NAME AND FUNCTION
26
O
Program Store Enable: The read strobe for external program memory. When the microcontroller
accesses external program memory, PSEN is driven low in order to enable memory devices. PSEN
is only active when external code accesses are performed.
35
29
I
External Access/Wait: The EA input determines whether the internal program memory of the
microcontroller is used for code execution. The value on the EA pin is latched as the external reset
input is released and applies during later execution. When latched as a 0, external program
memory is used exclusively, when latched as a 1, internal program memory will be used up to its
limit, and external program memory used above that point. After reset is released, this pin takes on
the function of bus Wait input. If Wait is asserted high during any external bus access, that cycle
will be extended until Wait is released. During EPROM programming, this pin is also the
programming supply voltage input.
XTAL1
21
15
I
Crystal 1: Input to the inverting amplifier used in the oscillator circuit and input to the internal clock
generator circuits.
XTAL2
20
14
O
Crystal 2: Output from the oscillator amplifier.
PLCC
LQFP
PSEN
32
EA/WAIT/
VPP
SPECIAL FUNCTION REGISTERS
NAME
DESCRIPTION
BIT FUNCTIONS AND ADDRESSES
SFR
ADDRESS
MSB
LSB
RESET
VALUE
BCR
Bus configuration register
46A
—
—
—
WAITD
BUSD
BC2
BC1
BC0
Note 1
BTRH
Bus timing register high byte
469
DW1
DW0
DWA1
DWA0
DR1
DR0
DRA1
DRA0
FF
BTRL
Bus timing register low byte
468
WM1
WM0
ALEW
—
CR1
CR0
CRA1
CRA0
EF
CS
DS
ES
Code segment
Data segment
Extra segment
443
441
442
00
00
00
33F
33E
33D
33C
33B
33A
339
338
—
—
—
—
ETI1
ERI1
ETI0
ERI0
IEH*
Interrupt enable high byte
427
337
336
335
334
333
332
331
330
IEL*
Interrupt enable low byte
426
EA
—
—
ET2
ET1
EX1
ET0
EX0
IPA0
Interrupt priority 0
4A0
—
PT0
—
PX0
00
IPA1
Interrupt priority 1
4A1
—
PT1
—
PX1
00
IPA2
Interrupt priority 2
4A2
—
—
—
PT2
00
IPA4
Interrupt priority 4
4A4
—
PTI0
—
PRI0
00
IPA5
Interrupt priority 5
4A5
P0*
P1*
P2*
Port 0
Port 1
Port 2
2002 Mar 25
430
431
432
—
PTI1
—
PRI1
00
00
387
386
385
384
383
382
381
380
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
38F
38E
38D
38C
38B
38A
389
388
T2EX
T2
TxD1
RxD1
A3
A2
A1
WRH
397
396
395
394
393
392
391
390
P2.7
P2.6
P2.5
P2.4
P2.3
P2.2
P2.1
P2.0
5
00
FF
FF
FF
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
DESCRIPTION
NAME
SFR
ADDRESS
BIT FUNCTIONS AND ADDRESSES
MSB
LSB
39F
39E
39D
39C
39B
39A
399
398
RD
WR
T1
T0
INT1
INT0
TxD0
RxD0
RESET
VALUE
P3*
Port 3
433
P0CFGA
Port 0 configuration A
470
Note 5
P1CFGA
Port 1 configuration A
471
Note 5
P2CFGA
Port 2 configuration A
472
Note 5
P3CFGA
Port 3 configuration A
473
Note 5
P0CFGB
Port 0 configuration B
4F0
Note 5
P1CFGB
Port 1 configuration B
4F1
Note 5
P2CFGB
Port 2 configuration B
4F2
Note 5
P3CFGB
Port 3 configuration B
4F3
Note 5
PCON*
Power control register
404
PSWH*
Program status word (high byte)
401
PSWL*
Program status word (low byte)
400
227
226
225
224
223
222
221
220
—
—
—
—
—
—
PD
IDL
20F
20E
20D
20C
20B
20A
209
208
SM
TM
RS1
RS0
IM3
IM2
IM1
IM0
207
206
205
204
203
202
201
200
C
AC
—
—
—
V
N
Z
217
216
215
214
213
212
211
210
C
AC
F0
RS1
RS0
V
F1
P
FF
00
Note 2
Note 2
PSW51*
80C51 compatible PSW
402
RTH0
Timer 0 extended reload,
high byte
Timer 1 extended reload,
high byte
Timer 0 extended reload, low byte
Timer 1 extended reload, low byte
455
00
457
00
454
456
00
00
RTH1
RTL0
RTL1
S0CON*
Serial port 0 control register
420
307
306
305
304
303
302
301
300
SM0_0
SM1_0
SM2_0
REN_0
TB8_0
RB8_0
TI_0
RI_0
30F
30E
30D
30C
30B
30A
309
308
—
—
—
—
FE0
BR0
OE0
STINT0
Note 3
00
S0STAT*
Serial port 0 extended status
421
S0BUF
S0ADDR
S0ADEN
Serial port 0 buffer register
Serial port 0 address register
Serial port 0 address enable
register
460
461
462
S1CON*
Serial port 1 control register
424
S1STAT*
Serial port 1 extended status
425
S1BUF
S1ADDR
S1ADEN
Serial port 1 buffer register
Serial port 1 address register
Serial port 1 address enable
register
464
465
466
SCR
System configuration register
440
—
21F
21E
21D
21C
21B
21A
219
218
SSEL*
Segment selection register
403
ESWEN
R6SEG
R5SEG
R4SEG
R3SEG
R2SEG
R1SEG
R0SEG
00
SWE
Software Interrupt Enable
47A
—
SWE7
SWE6
SWE5
SWE4
SWE3
SWE2
SWE1
00
2002 Mar 25
00
x
00
00
327
326
325
324
323
322
321
320
SM0_1
SM1_1
SM2_1
REN_1
TB8_1
RB8_1
TI_1
RI_1
32F
32E
32D
32C
32B
32A
329
328
—
—
—
—
FE1
BR1
OE1
STINT1
00
00
x
00
00
—
6
—
—
PT1
PT0
CM
PZ
00
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
DESCRIPTION
NAME
SFR
ADDRESS
BIT FUNCTIONS AND ADDRESSES
MSB
LSB
357
356
355
354
353
352
351
350
—
SWR7
SWR6
SWR5
SWR4
SWR3
SWR2
SWR1
RESET
VALUE
SWR*
Software Interrupt Request
42A
T2CON*
Timer 2 control register
418
T2MOD*
Timer 2 mode control
419
TH2
TL2
T2CAPH
Timer 2 high byte
Timer 2 low byte
Timer 2 capture register,
high byte
Timer 2 capture register,
low byte
459
458
45B
00
00
00
45A
00
T2CAPL
2C7
2C6
2C5
2C4
2C3
2C2
2C1
2C0
TF2
EXF2
RCLK0
TCLK0
EXEN2
TR2
C/T2
CP/RL2
2CF
2CE
2CD
2CC
2CB
2CA
2C9
2C8
—
—
RCLK1
TCLK1
—
—
T2OE
DCEN
287
286
285
284
283
282
281
280
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
TCON*
Timer 0 and 1 control register
410
TH0
TH1
TL0
TL1
Timer 0 high byte
Timer 1 high byte
Timer 0 low byte
Timer 1 low byte
451
453
450
452
TMOD
Timer 0 and 1 mode control
45C
TSTAT*
Timer 0 and 1 extended status
411
2FF
WDCON*
Watchdog control register
41F
PRE2
WDL
Watchdog timer reload
Watchdog feed 1
Watchdog feed 2
45F
45D
45E
WFEED1
WFEED2
00
00
00
00
00
00
00
00
GATE
C/T
M1
M0
GATE
C/T
M1
28F
28E
28D
28C
—
—
—
—
2FE
2FD
2FC
2FB
PRE1
PRE0
—
—
M0
28B
28A
289
288
—
T1OE
—
T0OE
2FA
2F9
2F8
WDRUN
WDTOF
—
00
00
Note 6
00
x
x
NOTES:
* SFRs are bit addressable.
1. At reset, the BCR register is loaded with the binary value 0000 0a11, where “a” is the value on the BUSW pin. This defaults the address bus
size to 20 bits since the XA-G37 has only 20 address lines.
2. SFR is loaded from the reset vector.
3. All bits except F1, F0, and P are loaded from the reset vector. Those bits are all 0.
4. Unimplemented bits in SFRs are X (unknown) at all times. Ones should not be written to these bits since they may be used for other
purposes in future XA derivatives. The reset value shown for these bits is 0.
5. Port configurations default to quasi-bidirectional when the XA begins execution from internal code memory after reset, based on the
condition found on the EA pin. Thus all PnCFGA registers will contain FF and PnCFGB registers will contain 00. When the XA begins
execution using external code memory, the default configuration for pins that are associated with the external bus will be push-pull. The
PnCFGA and PnCFGB register contents will reflect this difference.
6. The WDCON reset value is E6 for a Watchdog reset, E4 for all other reset causes.
7. The XA-G37 implements an 8-bit SFR bus, as stated in Chapter 8 of the XA User Guide. All SFR accesses must be 8-bit operations. Attempts
to write 16 bits to an SFR will actually write only the lower 8 bits. Sixteen bit SFR reads will return undefined data in the upper byte.
2002 Mar 25
7
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
generation, Timer 2 capture. Note that this single rate setting applies
to all of the timers.
XA-G37 TIMER/COUNTERS
The XA has two standard 16-bit enhanced Timer/Counters: Timer 0
and Timer 1. Additionally, it has a third 16-bit Up/Down
timer/counter, T2. A central timing generator in the XA core provides
the time-base for all XA Timers and Counters. The timer/event
counters can perform the following functions:
– Measure time intervals and pulse duration
– Count external events
– Generate interrupt requests
– Generate PWM or timed output waveforms
When timers T0, T1, or T2 are used in the counter mode, the
register will increment whenever a falling edge (high to low
transition) is detected on the external input pin corresponding to the
timer clock. These inputs are sampled once every 2 oscillator
cycles, so it can take as many as 4 oscillator cycles to detect a
transition. Thus the maximum count rate that can be supported is
Osc/4. The duty cycle of the timer clock inputs is not important, but
any high or low state on the timer clock input pins must be present
for 2 oscillator cycles before it is guaranteed to be “seen” by the
timer logic.
All of the timer/counters (Timer 0, Timer 1 and Timer 2) can be
independently programmed to operate either as timers or event
counters via the C/T bit in the TnCON register. All timers count up
unless otherwise stated. These timers may be dynamically read
during program execution.
Timer 0 and Timer 1
The “Timer” or “Counter” function is selected by control bits C/T in
the special function register TMOD. These two Timer/Counters have
four operating modes, which are selected by bit-pairs (M1, M0) in
the TMOD register. Timer modes 1, 2, and 3 in XA are kept identical
to the 80C51 timer modes for code compatibility. Only the mode 0 is
replaced in the XA by a more powerful 16-bit auto-reload mode. This
will give the XA timers a much larger range when used as time
bases.
The base clock rate of all of the timers is user programmable. This
applies to timers T0, T1, and T2 when running in timer mode (as
opposed to counter mode), and the watchdog timer. The clock
driving the timers is called TCLK and is determined by the setting of
two bits (PT1, PT0) in the System Configuration Register (SCR).
The frequency of TCLK may be selected to be the oscillator input
divided by 4 (Osc/4), the oscillator input divided by 16 (Osc/16), or
the oscillator input divided by 64 (Osc/64). This gives a range of
possibilities for the XA timer functions, including baud rate
SCR
Address:440
Not Bit Addressable
Reset Value: 00H
PT1
PT0
0
0
1
1
CM
0
1
0
1
PZ
The recommended M1, M0 settings for the different modes are
shown in Figure 2.
MSB
—
LSB
—
—
—
PT1
PT0
CM
PZ
OPERATING
Prescaler selection.
Osc/4
Osc/16
Osc/64
Reserved
Compatibility Mode allows the XA to execute most translated 80C51 code on the XA. The
XA register file must copy the 80C51 mapping to data memory and mimic the 80C51 indirect
addressing scheme.
Page Zero mode forces all program and data addresses to 16-bits only. This saves stack space
and speeds up execution but limits memory access to 64k.
SU00589
Figure 1. System Configuration Register (SCR)
TMOD
Address:45C
Not Bit Addressable
Reset Value: 00H
MSB
GATE
LSB
C/T
M1
M0
GATE
TIMER 1
GATE
C/T
M1
0
0
1
1
M0
0
1
0
1
C/T
M1
TIMER 0
Gating control when set. Timer/Counter “n” is enabled only while “INTn” pin is high and
“TRn” control bit is set. When cleared Timer “n” is enabled whenever “TRn” control bit is set.
Timer or Counter Selector cleared for Timer operation (input from internal system clock.)
Set for Counter operation (input from “Tn” input pin).
OPERATING
16-bit auto-reload timer/counter
16-bit non-auto-reload timer/counter
8-bit auto-reload timer/counter
Dual 8-bit timer mode (timer 0 only)
Figure 2. Timer/Counter Mode Control (TMOD) Register
2002 Mar 25
M0
8
SU00605
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
New Enhanced Mode 0
Mode 2 operation is the same for Timer/Counter 0.
For timers T0 or T1 the 13-bit count mode on the 80C51 (current
Mode 0) has been replaced in the XA with a 16-bit auto-reload
mode. Four additional 8-bit data registers (two per timer: RTHn and
RTLn) are created to hold the auto-reload values. In this mode, the
TH overflow will set the TF flag in the TCON register and cause both
the TL and TH counters to be loaded from the RTL and RTH
registers respectively.
The overflow rate for Timer 0 or Timer 1 in Mode 2 may be
calculated as follows:
These new SFRs will also be used to hold the TL reload data in the
8-bit auto-reload mode (Mode 2) instead of TH.
Timer 1 in Mode 3 simply holds its count. The effect is the same as
setting TR1 = 0.
The overflow rate for Timer 0 or Timer 1 in Mode 0 may be
calculated as follows:
Timer 0 in Mode 3 establishes TL0 and TH0 as two separate
counters. TL0 uses the Timer 0 control bits: C/T, GATE, TR0, INT0,
and TF0. TH0 is locked into a timer function and takes over the use
of TR1 and TF1 from Timer 1. Thus, TH0 now controls the “Timer 1”
interrupt.
Timer_Rate = Osc / (N * (256 – Timer_Reload_Value))
where N = the TCLK prescaler value: 4, 16, or 64.
Mode 3
Timer_Rate = Osc / (N * (65536 – Timer_Reload_Value))
where N = the TCLK prescaler value: 4 (default), 16, or 64.
Mode 3 is provided for applications requiring an extra 8-bit timer.
When Timer 0 is in Mode 3, Timer 1 can be turned on and off by
switching it out of and into its own Mode 3, or can still be used by
the serial port as a baud rate generator, or in fact, in any application
not requiring an interrupt.
Mode 1
Mode 1 is the 16-bit non-auto reload mode.
Mode 2
Mode 2 configures the Timer register as an 8-bit Counter (TLn) with
automatic reload. Overflow from TLn not only sets TFn, but also
reloads TLn with the contents of RTLn, which is preset by software.
The reload leaves THn unchanged.
TCON
Address:410
Bit Addressable
Reset Value: 00H
BIT
TCON.7
SYMBOL
TF1
TCON.6
TCON.5
TR1
TF0
TCON.4
TCON.3
TR0
IE1
TCON.2
IT1
TCON.1
IE0
TCON.0
IT0
MSB
TF1
LSB
TR1
TF0
TR0
IE1
IT1
IE0
IT0
FUNCTION
Timer 1 overflow flag. Set by hardware on Timer/Counter overflow.
This flag will not be set if T1OE (TSTAT.2) is set.
Cleared by hardware when processor vectors to interrupt routine, or by clearing the bit in software.
Timer 1 Run control bit. Set/cleared by software to turn Timer/Counter 1 on/off.
Timer 0 overflow flag. Set by hardware on Timer/Counter overflow.
This flag will not be set if T0OE (TSTAT.0) is set.
Cleared by hardware when processor vectors to interrupt routine, or by clearing the bit in software.
Timer 0 Run control bit. Set/cleared by software to turn Timer/Counter 0 on/off.
Interrupt 1 Edge flag. Set by hardware when external interrupt edge detected.
Cleared when interrupt processed.
Interrupt 1 type control bit. Set/cleared by software to specify falling edge/low level triggered
external interrupts.
Interrupt 0 Edge flag. Set by hardware when external interrupt edge detected.
Cleared when interrupt processed.
Interrupt 0 Type control bit. Set/cleared by software to specify falling edge/low level
triggered external interrupts.
SU00604C
Figure 3. Timer/Counter Control (TCON) Register
2002 Mar 25
9
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
T2CON
Address:418
Bit Addressable
Reset Value: 00H
BIT
T2CON.7
T2CON.6
T2CON.5
T2CON.4
T2CON.3
T2CON.2
T2CON.1
T2CON.0
MSB
TF2
LSB
EXF2
RCLK0
TCLK0
EXEN2
TR2
C2 or
T2
CP or
RL2
SYMBOL FUNCTION
TF2
Timer 2 overflow flag. Set by hardware on Timer/Counter overflow. Must be cleared by software.
TF2 will not be set when RCLK0, RCLK1, TCLK0, TCLK1 or T2OE=1.
EXF2
Timer 2 external flag is set when a capture or reload occurs due to a negative transition on T2EX (and
EXEN2 is set). This flag will cause a Timer 2 interrupt when this interrupt is enabled. EXF2 is cleared by
software.
RCLK0
Receive Clock Flag.
TCLK0
Transmit Clock Flag. RCLK0 and TCLK0 are used to select Timer 2 overflow rate as a clock source for
UART0 instead of Timer T1.
EXEN2
Timer 2 external enable bit allows a capture or reload to occur due to a negative transition on T2EX.
TR2
Start=1/Stop=0 control for Timer 2.
C2 or T2 Timer or counter select.
0=Internal timer
1=External event counter (falling edge triggered)
CP or RL2 Capture/Reload flag.
If CP/RL2 & EXEN2=1 captures will occur on negative transitions of T2EX.
If CP/RL2=0, EXEN2=1 auto reloads occur with either Timer 2 overflows or negative transitions at T2EX.
If RCLK or TCLK=1 the timer is set to auto reload on Timer 2 overflow, this bit has no effect.
SU00606
Figure 4. Timer/Counter 2 Control (T2CON) Register
Auto-Reload Mode (Up or Down Counter)
In the auto-reload mode, the timer registers are loaded with the
16-bit value in T2CAPH and T2CAPL when the count overflows.
T2CAPH and T2CAPL are initialized by software. If the EXEN2 bit in
T2CON is set, the timer registers will also be reloaded and the EXF2
flag set when a 1-to-0 transition occurs at input T2EX. The
auto-reload mode is shown in Figure 8.
New Timer-Overflow Toggle Output
In the XA, the timer module now has two outputs, which toggle on
overflow from the individual timers. The same device pins that are
used for the T0 and T1 count inputs are also used for the new
overflow outputs. An SFR bit (TnOE in the TSTAT register) is
associated with each counter and indicates whether Port-SFR data
or the overflow signal is output to the pin. These outputs could be
used in applications for generating variable duty cycle PWM outputs
(changing the auto-reload register values). Also variable frequency
(Osc/8 to Osc/8,388,608) outputs could be achieved by adjusting
the prescaler along with the auto-reload register values. With a
30.0MHz oscillator, this range would be 3.58Hz to 3.75MHz.
In this mode, Timer 2 can be configured to count up or down. This is
done by setting or clearing the bit DCEN (Down Counter Enable) in
the T2MOD special function register (see Table 1). The T2EX pin
then controls the count direction. When T2EX is high, the count is in
the up direction, when T2EX is low, the count is in the down
direction.
Timer T2
Timer 2 in the XA is a 16-bit Timer/Counter which can operate as
either a timer or as an event counter. This is selected by C/T2 in the
special function register T2CON. Upon timer T2 overflow/underflow,
the TF2 flag is set, which may be used to generate an interrupt. It
can be operated in one of three operating modes: auto-reload (up or
down counting), capture, or as the baud rate generator (for either or
both UARTs via SFRs T2MOD and T2CON). These modes are
shown in Table 1.
Figure 8 shows Timer 2, which will count up automatically, since
DCEN = 0. In this mode there are two options selected by bit
EXEN2 in the T2CON register. If EXEN2 = 0, then Timer 2 counts
up to FFFFH and sets the TF2 (Overflow Flag) bit upon overflow.
This causes the Timer 2 registers to be reloaded with the 16-bit
value in T2CAPL and T2CAPH, whose values are preset by
software. If EXEN2 = 1, a 16-bit reload can be triggered either by an
overflow or by a 1-to-0 transition at input T2EX. This transition also
sets the EXF2 bit. If enabled, either TF2 or EXF2 bit can generate
the Timer 2 interrupt.
Capture Mode
In the capture mode there are two options which are selected by bit
EXEN2 in T2CON. If EXEN2 = 0, then timer 2 is a 16-bit timer or
counter, which upon overflowing sets bit TF2, the timer 2 overflow
bit. This will cause an interrupt when the timer 2 interrupt is enabled.
In Figure 9, the DCEN = 1; this enables the Timer 2 to count up or
down. In this mode, the logic level of T2EX pin controls the direction
of count. When a logic ‘1’ is applied at pin T2EX, the Timer 2 will
count up. The Timer 2 will overflow at FFFFH and set the TF2 flag,
which can then generate an interrupt if enabled. This timer overflow,
also causes the 16-bit value in T2CAPL and T2CAPH to be
reloaded into the timer registers TL2 and TH2, respectively.
If EXEN2 = 1, then Timer 2 still does the above, but with the added
feature that a 1-to-0 transition at external input T2EX causes the
current value in the Timer 2 registers, TL2 and TH2, to be captured
into registers RCAP2L and RCAP2H, respectively. In addition, the
transition at T2EX causes bit EXF2 in T2CON to be set. This will
cause an interrupt in the same fashion as TF2 when the Timer 2
interrupt is enabled. The capture mode is illustrated in Figure 7.
2002 Mar 25
A logic ‘0’ at pin T2EX causes Timer 2 to count down. When
counting down, the timer value is compared to the 16-bit value
contained in T2CAPH and T2CAPL. When the value is equal, the
10
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
timer register is loaded with FFFF hex. The underflow also sets the
TF2 flag, which can generate an interrupt if enabled.
Timer/Counter 2 or (2) to output a 50% duty cycle clock ranging from
3.58Hz to 3.75MHz at a 30MHz operating frequency.
The external flag EXF2 toggles when Timer 2 underflows or
overflows. This EXF2 bit can be used as a 17th bit of resolution, if
needed. the EXF2 flag does not generate an interrupt in this mode.
As the baud rate generator, timer T2 is incremented by TCLK.
To configure the Timer/Counter 2 as a clock generator, bit C/T2 (in
T2CON) must be cleared and bit T20E in T2MOD must be set. Bit
TR2 (T2CON.2) also must be set to start the timer.
The Clock-Out frequency depends on the oscillator frequency and
the reload value of Timer 2 capture registers (TCAP2H, TCAP2L) as
shown in this equation:
Baud Rate Generator Mode
By setting the TCLKn and/or RCLKn in T2CON or T2MOD, the
Timer 2 can be chosen as the baud rate generator for either or both
UARTs. The baud rates for transmit and receive can be
simultaneously different.
2
TCLK
(65536 * TCAP2H, TCAP2L)
In the Clock-Out mode Timer 2 roll-overs will not generate an
interrupt. This is similar to when it is used as a baud-rate generator.
It is possible to use Timer 2 as a baud-rate generator and a clock
generator simultaneously. Note, however, that the baud-rate will be
1/8 of the Clock-Out frequency.
Programmable Clock-Out
A 50% duty cycle clock can be programmed to come out on P1.6.
This pin, besides being a regular I/O pin, has two alternate
functions. It can be programmed (1) to input the external clock for
Table 1. Timer 2 Operating Modes
TR2
CP/RL2
RCLK+TCLK
DCEN
0
X
X
X
Timer off (stopped)
1
0
0
0
16-bit auto-reload, counting up
1
0
0
1
16-bit auto-reload, counting up or down depending on T2EX pin
1
1
0
X
16-bit capture
1
X
1
X
Baud rate generator
TSTAT
Address:411
Bit Addressable
Reset Value: 00H
BIT
TSTAT.2
SYMBOL
T1OE
TSTAT.0
T0OE
MODE
MSB
—
LSB
—
—
—
—
T1OE
—
T0OE
FUNCTION
When 0, this bit allows the T1 pin to clock Timer 1 when in the counter mode.
When 1, T1 acts as an output and toggles at every Timer 1 overflow.
When 0, this bit allows the T0 pin to clock Timer 0 when in the counter mode.
When 1, T0 acts as an output and toggles at every Timer 0 overflow.
SU00612B
Figure 5. Timer 0 And 1 Extended Status (TSTAT)
T2MOD
Address:419
Bit Addressable
Reset Value: 00H
MSB
—
LSB
—
RCLK1
TCLK1
—
—
T2OE
DCEN
BIT
SYMBOL FUNCTION
T2MOD.5 RCLK1
Receive Clock Flag.
T2MOD.4 TCLK1
Transmit Clock Flag. RCLK1 and TCLK1 are used to select Timer 2 overflow rate as a clock source
for UART1 instead of Timer T1.
T2MOD.1 T2OE
When 0, this bit allows the T2 pin to clock Timer 2 when in the counter mode.
When 1, T2 acts as an output and toggles at every Timer 2 overflow.
T2MOD.0 DCEN
Controls count direction for Timer 2 in autoreload mode.
DCEN=0 counter set to count up only
DCEN=1 counter set to count up or down, depending on T2EX (see text).
SU00610B
Figure 6. Timer 2 Mode Control (T2MOD)
2002 Mar 25
11
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
TCLK
C/T2 = 0
TL2
(8-bits)
TH2
(8-bits)
TF2
C/T2 = 1
T2 Pin
Control
Transition
Detector
TR2
Capture
Timer 2
Interrupt
T2CAPL
T2CAPH
T2EX Pin
EXF2
Control
EXEN2
SU00704
Figure 7. Timer 2 in Capture Mode
TCLK
C/T2 = 0
TL2
(8-bits)
TH2
(8-bits)
C/T2 = 1
T2 Pin
Control
TR2
Reload
Transition
Detector
T2CAPL
T2CAPH
TF2
Timer 2
Interrupt
T2EX Pin
EXF2
Control
EXEN2
SU00705
Figure 8. Timer 2 in Auto-Reload Mode (DCEN = 0)
(DOWN COUNTING RELOAD VALUE)
FFH
FFH
TOGGLE
EXF2
TCLK
C/T2 = 0
OVERFLOW
TL2
T2 PIN
TH2
TF2
INTERRUPT
C/T2 = 1
CONTROL
TR2
COUNT
DIRECTION
1 = UP
0 = DOWN
T2CAPL
T2CAPH
(UP COUNTING RELOAD VALUE)
Figure 9. Timer 2 Auto Reload Mode (DCEN = 1)
2002 Mar 25
12
T2EX PIN
SU00706
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
The software must be written so that a feed operation takes place
every tD seconds from the last feed operation. Some tradeoffs may
need to be made. It is not advisable to include feed operations in
minor loops or in subroutines unless the feed operation is a specific
subroutine.
WATCHDOG TIMER
The watchdog timer subsystem protects the system from incorrect
code execution by causing a system reset when the watchdog timer
underflows as a result of a failure of software to feed the timer prior
to the timer reaching its terminal count. It is important to note that
the watchdog timer is running after any type of reset and must be
turned off by user software if the application does not use the
watchdog function.
To turn the watchdog timer completely off, the following code
sequence should be used:
mov.b
mov.b
mov.b
Watchdog Function
The watchdog consists of a programmable prescaler and the main
timer. The prescaler derives its clock from the TCLK source that also
drives timers 0, 1, and 2. The watchdog timer subsystem consists of
a programmable 13-bit prescaler, and an 8-bit main timer. The main
timer is clocked (decremented) by a tap taken from one of the top
8-bits of the prescaler as shown in Figure 10. The clock source for
the prescaler is the same as TCLK (same as the clock source for
the timers). Thus the main counter can be clocked as often as once
every 32 TCLKs (see Table 2). The watchdog generates an
underflow signal (and is autoloaded from WDL) when the watchdog
is at count 0 and the clock to decrement the watchdog occurs. The
watchdog is 8 bits wide and the autoload value can range from 0 to
FFH. (The autoload value of 0 is permissible since the prescaler is
cleared upon autoload).
wdcon,#0
; set WD control register to clear WDRUN.
wfeed1,#A5h ; do watchdog feed part 1
wfeed2,#5Ah ; do watchdog feed part 2
This sequence assumes that the watchdog timer is being turned off
at the beginning of initialization code and that the XA interrupt
system has not yet been enabled. If the watchdog timer is to be
turned off at a point when interrupts may be enabled, instructions to
disable and re-enable interrupts should be added to this sequence.
Watchdog Control Register (WDCON)
The reset values of the WDCON and WDL registers will be such that
the watchdog timer has a timeout period of 4 × 4096 × tOSC and the
watchdog is running. WDCON can be written by software but the
changes only take effect after executing a valid watchdog feed
sequence.
This leads to the following user design equations. Definitions: tOSC
is the oscillator period, N is the selected prescaler tap value, W is
the main counter autoload value, P is the prescaler value from
Table 2, tMIN is the minimum watchdog time-out value (when the
autoload value is 0), tMAX is the maximum time-out value (when the
autoload value is FFH), tD is the design time-out value.
Table 2. Prescaler Select Values in WDCON
PRE2
PRE1
PRE0
DIVISOR
0
0
0
32
0
0
1
64
tMIN = tOSC × 4 × 32 (W = 0, N = 4)
0
1
0
128
tMAX = tOSC × 64 × 4096 × 256 (W = 255, N = 64)
0
1
1
256
tD = tOSC × N × P × (W + 1)
1
0
0
512
1
0
1
1024
1
1
0
2048
1
1
1
4096
The watchdog timer is not directly loadable by the user. Instead, the
value to be loaded into the main timer is held in an autoload register.
In order to cause the main timer to be loaded with the appropriate
value, a special sequence of software action must take place. This
operation is referred to as feeding the watchdog timer.
Watchdog Detailed Operation
To feed the watchdog, two instructions must be sequentially
executed successfully. No intervening SFR accesses are allowed,
so interrupts should be disabled before feeding the watchdog. The
instructions should move A5H to the WFEED1 register and then
5AH to the WFEED2 register. If WFEED1 is correctly loaded and
WFEED2 is not correctly loaded, then an immediate watchdog reset
will occur. The program sequence to feed the watchdog timer or
cause new WDCON settings to take effect is as follows:
clr
mov.b
mov.b
setb
ea
wfeed1,#A5h
wfeed2,#5Ah
ea
When external RESET is applied, the following takes place:
• Watchdog run control bit set to ON (1).
• Autoload register WDL set to 00 (min. count).
• Watchdog time-out flag cleared.
• Prescaler is cleared.
• Prescaler tap set to the highest divide.
• Autoload takes place.
; disable global interrupts.
; do watchdog feed part 1
; do watchdog feed part 2
; re-enable global interrupts.
When coming out of a hardware reset, the software should load the
autoload register and then feed the watchdog (cause an autoload).
This sequence assumes that the XA interrupt system is enabled and
there is a possibility of an interrupt request occurring during the feed
sequence. If an interrupt was allowed to be serviced and the service
routine contained any SFR access, it would trigger a watchdog
reset. If it is known that no interrupt could occur during the feed
sequence, the instructions to disable and re-enable interrupts may
be removed.
2002 Mar 25
If the watchdog is running and happens to underflow at the time the
external RESET is applied, the watchdog time-out flag will be
cleared.
13
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
WDL
WATCHDOG FEED SEQUENCE
MOV WFEED1,#A5H
MOV WFEED2,#5AH
TCLK
8–BIT DOWN
COUNTER
PRESCALER
PRE2
PRE1
PRE0
—
—
WDRUN
INTERNAL RESET
WDTOF
—
WDCON
SU00581A
Figure 10. Watchdog Timer in XA-G37
Each UART baud rate is determined by either a fixed division of the
oscillator (in UART modes 0 and 2) or by the timer 1 or timer 2
overflow rate (in UART modes 1 and 3).
When the watchdog underflows, the following action takes place
(see Figure 10):
• Autoload takes place.
• Watchdog time-out flag is set
• Watchdog run bit unchanged.
• Autoload (WDL) register unchanged.
• Prescaler tap unchanged.
• All other device action same as external reset.
Timer 1 defaults to clock both UART0 and UART1. Timer 2 can be
programmed to clock either UART0 through T2CON (via bits R0CLK
and T0CLK) or UART1 through T2MOD (via bits R1CLK and
T1CLK). In this case, the UART not clocked by T2 could use T1 as
the clock source.
The serial port receive and transmit registers are both accessed at
Special Function Register SnBUF. Writing to SnBUF loads the
transmit register, and reading SnBUF accesses a physically
separate receive register.
Note that if the watchdog underflows, the program counter will be
loaded from the reset vector as in the case of an internal reset. The
watchdog time-out flag can be examined to determine if the
watchdog has caused the reset condition. The watchdog time-out
flag bit can be cleared by software.
The serial port can operate in 4 modes:
Mode 0: Serial I/O expansion mode. Serial data enters and exits
through RxDn. TxDn outputs the shift clock. 8 bits are
transmitted/received (LSB first). (The baud rate is fixed at 1/16 the
oscillator frequency.)
WDCON Register Bit Definitions
WDCON.7 PRE2
Prescaler Select 2, reset to 1
WDCON.6 PRE1
Prescaler Select 1, reset to 1
WDCON.5 PRE0
Prescaler Select 0, reset to 1
WDCON.4 —
WDCON.3 —
WDCON.2 WDRUN Watchdog Run Control bit, reset to 1
WDCON.1 WDTOF
Timeout flag
WDCON.0 —
Mode 1: Standard 8-bit UART mode. 10 bits are transmitted
(through TxDn) or received (through RxDn): a start bit (0), 8 data
bits (LSB first), and a stop bit (1). On receive, the stop bit goes into
RB8 in Special Function Register SnCON. The baud rate is variable.
Mode 2: Fixed rate 9-bit UART mode. 11 bits are transmitted
(through TxD) or received (through RxD): start bit (0), 8 data bits
(LSB first), a programmable 9th data bit, and a stop bit (1). On
Transmit, the 9th data bit (TB8_n in SnCON) can be assigned the
value of 0 or 1. Or, for example, the parity bit (P, in the PSW) could
be moved into TB8_n. On receive, the 9th data bit goes into RB8_n
in Special Function Register SnCON, while the stop bit is ignored.
The baud rate is programmable to 1/32 of the oscillator frequency.
UARTs
The XA-G37 includes 2 UART ports that are compatible with the
enhanced UART used on the 8xC51FB. Baud rate selection is
somewhat different due to the clocking scheme used for the XA
timers.
Mode 3: Standard 9-bit UART mode. 11 bits are transmitted
(through TxDn) or received (through RxDn): a start bit (0), 8 data
bits (LSB first), a programmable 9th data bit, and a stop bit (1).
In fact, Mode 3 is the same as Mode 2 in all respects except baud
rate. The baud rate in Mode 3 is variable.
Some other enhancements have been made to UART operation.
The first is that there are separate interrupt vectors for each UART’s
transmit and receive functions. The UART transmitter has been
double buffered, allowing packed transmission of data with no gaps
between bytes and less critical interrupt service routine timing. A
break detect function has been added to the UART. This operates
independently of the UART itself and provides a start-of-break status
bit that the program may test. Finally, an Overrun Error flag has
been added to detect missed characters in the received data
stream. The double buffered UART transmitter may require some
software changes in code written for the original XA-G37 single
buffered UART.
2002 Mar 25
In all four modes, transmission is initiated by any instruction that
uses SnBUF as a destination register. Reception is initiated in
Mode 0 by the condition RI_n = 0 and REN_n = 1. Reception is
initiated in the other modes by the incoming start bit if REN_n = 1.
14
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
The recommended method of using the double buffering in the
application program is to have the interrupt service routine handle a
single byte for each interrupt occurrence. In this manner the
program essentially does not require any special considerations for
double buffering. Unless higher priority interrupts cause delays in
the servicing of the UART transmitter interrupt, the double buffering
will result in transmitted bytes being tightly packed with no
intervening gaps.
Serial Port Control Register
The serial port control and status register is the Special Function
Register SnCON, shown in Figure 12. This register contains not only
the mode selection bits, but also the 9th data bit for transmit and
receive (TB8_n and RB8_n), and the serial port interrupt bits (TI_n
and RI_n).
TI Flag
In order to allow easy use of the double buffered UART transmitter
feature, the TI_n flag is set by the UART hardware under two
conditions. The first condition is the completion of any byte
transmission. This occurs at the end of the stop bit in modes 1, 2, or
3, or at the end of the eighth data bit in mode 0. The second
condition is when SnBUF is written while the UART transmitter is
idle. In this case, the TI_n flag is set in order to indicate that the
second UART transmitter buffer is still available.
9-bit Mode
Please note that the ninth data bit (TB8) is not double buffered. Care
must be taken to insure that the TB8 bit contains the intended data
at the point where it is transmitted. Double buffering of the UART
transmitter may be bypassed as a simple means of synchronizing
TB8 to the rest of the data stream.
Bypassing Double Buffering
The UART transmitter may be used as if it is single buffered. The
recommended UART transmitter interrupt service routine (ISR)
technique to bypass double buffering first clears the TI_n flag upon
entry into the ISR, as in standard practice. This clears the interrupt
that activated the ISR. Secondly, the TI_n flag is cleared
immediately following each write to SnBUF. This clears the interrupt
flag that would otherwise direct the program to write to the second
transmitter buffer. If there is any possibility that a higher priority
interrupt might become active between the write to SnBUF and the
clearing of the TI_n flag, the interrupt system may have to be
temporarily disabled during that sequence by clearing, then setting
the EA bit in the IEL register.
Typically, UART transmitters generate one interrupt per byte
transmitted. In the case of the XA UART, one additional interrupt is
generated as defined by the stated conditions for setting the TI_n
flag. This additional interrupt does not occur if double buffering is
bypassed as explained below. Note that if a character oriented
approach is used to transmit data through the UART, there could be
a second interrupt for each character transmitted, depending on the
timing of the writes to SBUF. For this reason, it is generally better to
bypass double buffering when the UART transmitter is used in
character oriented mode. This is also true if the UART is polled
rather than interrupt driven, and when transmission is character
oriented rather than message or string oriented. The interrupt occurs
at the end of the last byte transmitted when the UART becomes idle.
Among other things, this allows a program to determine when a
message has been transmitted completely. The interrupt service
routine should handle this additional interrupt.
2002 Mar 25
Note Regarding Older XA-G37 Devices
Older versions of the XA-G30, XA-G37, and XA-G35 emulation
bondout devices do not have the double buffering feature enabled.
Contact factory for details.
15
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
CLOCKING SCHEME/BAUD RATE GENERATION
Using Timer 2 to Generate Baud Rates
The XA UARTS clock rates are determined by either a fixed division
(modes 0 and 2) of the oscillator clock or by the Timer 1 or Timer 2
overflow rate (modes 1 and 3).
Timer T2 is a 16-bit up/down counter in XA. As a baud rate
generator, timer 2 is selected as a clock source for either/both
UART0 and UART1 transmitters and/or receivers by setting TCLKn
and/or RCLKn in T2CON and T2MOD. As the baud rate generator,
T2 is incremented as Osc/N where N = 4, 16 or 64 depending on
TCLK as programmed in the SCR bits PT1, and PTO. So, if T2 is
the source of one UART, the other UART could be clocked by either
T1 overflow or fixed clock, and the UARTs could run independently
with different baud rates.
The clock for the UARTs in XA runs at 16x the Baud rate. If the
timers are used as the source for Baud Clock, since maximum
speed of timers/Baud Clock is Osc/4, the maximum baud rate is
timer overflow divided by 16 i.e. Osc/64.
In Mode 0, it is fixed at Osc/16. In Mode 2, however, the fixed rate is
Osc/32.
Pre-scaler
for all Timers T0,1,2
T0 1 2
controlled by PT1, PT0
bits in SCR
00
Osc/4
01
Osc/16
10
Osc/64
11
reserved
T2CON
0x418
T2MOD
0x419
Baud Rate for UART Mode 0:
Baud_Rate = Osc/16
bit5
bit4
RCLK0
TCLK0
bit5
bit4
RCLK1
TCLK1
Prescaler Select for Timer Clock (TCLK)
Baud Rate calculation for UART Mode 1 and 3:
Baud_Rate = Timer_Rate/16
SCR
0x440
bit3
bit2
PT1
PT0
Timer_Rate = Osc/(N*(Timer_Range– Timer_Reload_Value))
where N = the TCLK prescaler value: 4, 16, or 64.
and Timer_Range = 256 for timer 1 in mode 2.
65536 for timer 1 in mode 0 and timer 2
in count up mode.
The timer reload value may be calculated as follows:
Timer_Reload_Value = Timer_Range–(Osc/(Baud_Rate*N*16))
NOTES:
1. The maximum baud rate for a UART in mode 1 or 3 is Osc/64.
2. The lowest possible baud rate (for a given oscillator frequency
and N value) may be found by using a timer reload value of 0.
3. The timer reload value may never be larger than the timer range.
4. If a timer reload value calculation gives a negative or fractional
result, the baud rate requested is not possible at the given
oscillator frequency and N value.
Baud Rate for UART Mode 2:
Baud_Rate = Osc/32
SnSTAT Address: S0STAT 421
S1STAT 425
Bit Addressable
Reset Value: 00H
MSB
—
LSB
—
—
—
FEn
BRn
OEn
STINTn
BIT
SYMBOL FUNCTION
SnSTAT.3 FEn
Framing Error flag is set when the receiver fails to see a valid STOP bit at the end of the frame.
Cleared by software.
SnSTAT.2 BRn
Break Detect flag is set if a character is received with all bits (including STOP bit) being logic ‘0’. Thus
it gives a “Start of Break Detect” on bit 8 for Mode 1 and bit 9 for Modes 2 and 3. The break detect
feature operates independently of the UARTs and provides the START of Break Detect status bit that
a user program may poll. Cleared by software.
SnSTAT.1 OEn
Overrun Error flag is set if a new character is received in the receiver buffer while it is still full (before
the software has read the previous character from the buffer), i.e., when bit 8 of a new byte is
received while RI in SnCON is still set. Cleared by software.
SnSTAT.0 STINTn
This flag must be set to enable any of the above status flags to generate a receive interrupt (RIn). The
only way it can be cleared is by a software write to this register.
SU00607B
Figure 11. Serial Port Extended Status (SnSTAT) Register
(See also Figure 13 regarding Framing Error flag)
2002 Mar 25
16
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
Given slave address or addresses. All of the slaves may be
contacted by using the Broadcast address. Two special Function
Registers are used to define the slave’s address, SADDR, and the
address mask, SADEN. SADEN is used to define which bits in the
SADDR are to be used and which bits are “don’t care”. The SADEN
mask can be logically ANDed with the SADDR to create the “Given”
address which the master will use for addressing each of the slaves.
Use of the Given address allows multiple slaves to be recognized
while excluding others. The following examples will help to show the
versatility of this scheme:
UART INTERRUPT SCHEME
There are separate interrupt vectors for each UART’s transmit and
receive functions.
Table 3. Vector Locations for UARTs in XA
Vector Address
Interrupt Source
Arbitration
A0H – A3H
UART 0 Receiver
7
A4H – A7H
UART 0 Transmitter
8
A8H – ABH
UART 1 Receiver
9
ACH – AFH
UART 1 Transmitter
10
NOTE:
The transmit and receive vectors could contain the same ISR
address to work like a 8051 interrupt scheme
Error Handling, Status Flags and Break Detect
The UARTs in XA has the following error flags; see Figure 11.
SADDR =
SADEN =
Given
=
1100 0000
1111 1101
1100 00X0
Slave 1
SADDR =
SADEN =
Given
=
1100 0000
1111 1110
1100 000X
In the above example SADDR is the same and the SADEN data is
used to differentiate between the two slaves. Slave 0 requires a 0 in
bit 0 and it ignores bit 1. Slave 1 requires a 0 in bit 1 and bit 0 is
ignored. A unique address for Slave 0 would be 1100 0010 since
slave 1 requires a 0 in bit 1. A unique address for slave 1 would be
1100 0001 since a 1 in bit 0 will exclude slave 0. Both slaves can be
selected at the same time by an address which has bit 0 = 0 (for
slave 0) and bit 1 = 0 (for slave 1). Thus, both could be addressed
with 1100 0000.
Multiprocessor Communications
Modes 2 and 3 have a special provision for multiprocessor
communications. In these modes, 9 data bits are received. The 9th
one goes into RB8. Then comes a stop bit. The port can be
programmed such that when the stop bit is received, the serial port
interrupt will be activated only if RB8 = 1. This feature is enabled by
setting bit SM2 in SCON. A way to use this feature in multiprocessor
systems is as follows:
In a more complex system the following could be used to select
slaves 1 and 2 while excluding slave 0:
When the master processor wants to transmit a block of data to one
of several slaves, it first sends out an address byte which identifies
the target slave. An address byte differs from a data byte in that the
9th bit is 1 in an address byte and 0 in a data byte. With SM2 = 1, no
slave will be interrupted by a data byte. An address byte, however,
will interrupt all slaves, so that each slave can examine the received
byte and see if it is being addressed. The addressed slave will clear
its SM2 bit and prepare to receive the data bytes that will be coming.
The slaves that weren’t being addressed leave their SM2s set and
go on about their business, ignoring the coming data bytes.
SM2 has no effect in Mode 0, and in Mode 1 can be used to check
the validity of the stop bit although this is better done with the
Framing Error (FE) flag. In a Mode 1 reception, if SM2 = 1, the
receive interrupt will not be activated unless a valid stop bit is
received.
Slave 0
SADDR =
SADEN =
Given
=
1100 0000
1111 1001
1100 0XX0
Slave 1
SADDR =
SADEN =
Given
=
1110 0000
1111 1010
1110 0X0X
Slave 2
SADDR =
SADEN =
Given
=
1110 0000
1111 1100
1110 00XX
In the above example the differentiation among the 3 slaves is in the
lower 3 address bits. Slave 0 requires that bit 0 = 0 and it can be
uniquely addressed by 1110 0110. Slave 1 requires that bit 1 = 0 and
it can be uniquely addressed by 1110 and 0101. Slave 2 requires
that bit 2 = 0 and its unique address is 1110 0011. To select Slaves 0
and 1 and exclude Slave 2 use address 1110 0100, since it is
necessary to make bit 2 = 1 to exclude slave 2.
Automatic Address Recognition
Automatic Address Recognition is a feature which allows the UART
to recognize certain addresses in the serial bit stream by using
hardware to make the comparisons. This feature saves a great deal
of software overhead by eliminating the need for the software to
examine every serial address which passes by the serial port. This
feature is enabled by setting the SM2 bit in SCON. In the 9 bit UART
modes, mode 2 and mode 3, the Receive Interrupt flag (RI) will be
automatically set when the received byte contains either the “Given”
address or the “Broadcast” address. The 9 bit mode requires that
the 9th information bit is a 1 to indicate that the received information
is an address and not data. Automatic address recognition is shown
in Figure 14.
The Broadcast Address for each slave is created by taking the
logical OR of SADDR and SADEN. Zeros in this result are teated as
don’t-cares. In most cases, interpreting the don’t-cares as ones, the
broadcast address will be FF hexadecimal.
Upon reset SADDR and SADEN are loaded with 0s. This produces
a given address of all “don’t cares” as well as a Broadcast address
of all “don’t cares”. This effectively disables the Automatic
Addressing mode and allows the microcontroller to use standard
UART drivers which do not make use of this feature.
Using the Automatic Address Recognition feature allows a master to
selectively communicate with one or more slaves by invoking the
2002 Mar 25
Slave 0
17
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
SnCON
Address:
S0CON 420
S1CON 424
MSB
LSB
SM0
Bit Addressable
Reset Value: 00H
SM1
SM2
REN
TB8
RB8
TI
RI
Where SM0, SM1 specify the serial port mode, as follows:
SM0
0
0
1
1
SM1
0
1
0
1
Mode
0
1
2
3
Description
shift register
8-bit UART
9-bit UART
9-bit UART
Baud Rate
fOSC/16
variable
fOSC/32
variable
BIT
SYMBOL FUNCTION
SnCON.5 SM2
Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or 3, if SM2 is set to 1, then RI
will not be activated if the received 9th data bit (RB8) is 0. In Mode 1, if SM2=1 then RI will not be activated if a
valid stop bit was not received. In Mode 0, SM2 should be 0.
SnCON.4 REN
Enables serial reception. Set by software to enable reception. Clear by software to disable reception.
SnCON.3 TB8
The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software as desired. The TB8 bit is not
double buffered. See text for details.
SnCON.2 RB8
In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, if SM2=0, RB8 is the stop bit that was
received. In Mode 0, RB8 is not used.
SnCON.1 TI
Transmit interrupt flag. Set when another byte may be written to the UART transmitter. See text for details.
Must be cleared by software.
SnCON.0 RI
Receive interrupt flag. Set by hardware at the end of the 8th bit time in Mode 0, or at the end of the stop bit time
in the other modes (except see SM2). Must be cleared by software.
SU00597C
Figure 12. Serial Port Control (SnCON) Register
D0
D1
D2
D3
D4
D5
D6
D7
D8
DATA BYTE
START
BIT
ONLY IN
MODE 2, 3
STOP
BIT
if 0, sets FE
—
—
—
—
FEn
BRn
OEn
STINTn
SnSTAT
SU00598
Figure 13. UART Framing Error Detection
D0
D1
D2
D3
SM0_n
1
1
D4
SM1_n
D5
D6
SM2_n
REN_n
TB8_n
1
X
1
1
0
D7
D8
RB8_n
TI_n
RI_n
SnCON
RECEIVED ADDRESS D0 TO D7
COMPARATOR
PROGRAMMED ADDRESS
IN UART MODE 2 OR MODE 3 AND SM2 = 1:
INTERRUPT IF REN=1, RB8=1 AND “RECEIVED ADDRESS” = “PROGRAMMED ADDRESS”
– WHEN OWN ADDRESS RECEIVED, CLEAR SM2 TO RECEIVE DATA BYTES
– WHEN ALL DATA BYTES HAVE BEEN RECEIVED: SET SM2 TO WAIT FOR NEXT ADDRESS.
SU00613
Figure 14. UART Multiprocessor Communication, Automatic Address Recognition
2002 Mar 25
18
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
As it is brought high again, an exception is generated which causes
the processor to jump to the address contained in the memory
location 0000. The destination of the reset jump must be located in
the first 64k of code address on power-up, all vectors are 16-bit
values and so point to page zero addresses only. After a reset the
RAM contents are indeterminate.
I/O PORT OUTPUT CONFIGURATION
Each I/O port pin can be user configured to one of 4 output types.
The types are Quasi-bidirectional (essentially the same as standard
80C51 family I/O ports), Open-Drain, Push-Pull, and Off (high
impedance). The default configuration after reset is
Quasi-bidirectional. However, in the ROMless mode (the EA pin is
low at reset), the port pins that comprise the external data bus will
default to push-pull outputs.
VDD
I/O port output configurations are determined by the settings in port
configuration SFRs. There are 2 SFRs for each port, called
PnCFGA and PnCFGB, where “n” is the port number. One bit in
each of the 2 SFRs relates to the output setting for the
corresponding port pin, allowing any combination of the 2 output
types to be mixed on those port pins. For instance, the output type
of port 1 pin 3 is controlled by the setting of bit 3 in the SFRs
P1CFGA and P1CFGB.
R
RST
C
SOME TYPICAL VALUES FOR R AND C:
R = 100K, C = 1.0 µF
R = 1.0M, C = 0.1 µF
(ASSUMING THAT THE VDD RISE TIME IS 1ms OR LESS)
Table 4 shows the configuration register settings for the 4 port
output types. The electrical characteristics of each output type may
be found in the DC Characteristic table.
PnCFGA
Port Output Mode
0
0
Open Drain
0
1
Quasi-bidirectional
1
0
Off (high impedance)
1
1
Push-Pull
RESET OPTIONS
The EA pin is sampled on the rising edge of the RST pulse, and
determines whether the device is to begin execution from internal or
external code memory. EA pulled high configures the XA in
single-chip mode. If EA is driven low, the device enters ROMless
mode. After Reset is released, the EA/WAIT pin becomes a bus wait
signal for external bus transactions.
The BUSW/P3.5 pin is weakly pulled high while reset is asserted,
allowing simple biasing of the pin with a resistor to ground to select
the alternate bus width. If the BUSW pin is not driven at reset, the
weak pullup will cause a 1 to be loaded for the bus width, giving a
16-bit external bus. BUSW may be pulled low with a 2.7K or smaller
value resistor, giving an 8-bit external bus. The bus width setting
from the BUSW pin may be overridden by software once the user
program is running.
NOTE:
Mode changes may cause glitches to occur during transitions. When
modifying both registers, WRITE instructions should be carried out
consecutively.
EXTERNAL BUS
The external program/data bus allows for 8-bit or 16-bit bus width,
and address sizes from 12 to 20 bits. The bus width is selected by
an input at reset (see Reset Options below), while the address size
is set by the program in a configuration register. If all off-chip code is
selected (through the use of the EA pin), the initial code fetches will
be done with the maximum address size (20 bits).
Both EA and BUSW must be held for three oscillator clock times
after reset is deasserted to guarantee that their values are latched
correctly.
POWER REDUCTION MODES
The XA-G37 supports Idle and Power Down modes of power
reduction. The idle mode leaves some peripherals running to allow
them to wake up the processor when an interrupt is generated. The
power down mode stops the oscillator in order to minimize power.
The processor can be made to exit power down mode via reset or
one of the external interrupt inputs. In order to use an external
interrupt to re-activate the XA while in power down mode, the
external interrupt must be enabled and be configured to level
sensitive mode. In power down mode, the power supply voltage may
be reduced to the RAM keep-alive voltage (2 V), retaining the RAM,
register, and SFR values at the point where the power down mode
was entered.
RESET
The device is reset whenever a logic “0“ is applied to RST for at
least 10 microseconds, placing a low level on the pin re-initializes
the on-chip logic. Reset must be asserted when power is initially
applied to the XA and held until the oscillator is running.
The duration of reset must be extended when power is initially
applied or when using reset to exit power down mode. This is due to
the need to allow the oscillator time to start up and stabilize. For
most power supply ramp up conditions, this time is 10 milliseconds.
2002 Mar 25
SU00702
Figure 15. Recommended Reset Circuit
Table 4. Port Configuration Register Settings
PnCFGB
XA
19
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
The XA-G37 supports a total of 9 maskable event interrupt sources
(for the various XA peripherals), seven software interrupts, 5
exception interrupts (plus reset), and 16 traps. The maskable event
interrupts share a global interrupt disable bit (the EA bit in the IEL
register) and each also has a separate individual interrupt enable bit
(in the IEL or IEH registers). Only three bits of the IPA register
values are used on the XA-G3. Each event interrupt can be set to
occur at one of 8 priority levels via bits in the Interrupt Priority (IP)
registers, IPA0 through IPA5. The value 0 in the IPA field gives the
interrupt priority 0, in effect disabling the interrupt. A value of 1 gives
the interrupt a priority of 9, the value 2 gives priority 10, etc. The
result is the same as if all four bits were used and the top bit set for
all values except 0. Details of the priority scheme may be found in
the XA User Guide.
INTERRUPTS
The XA-G37 supports 38 vectored interrupt sources. These include
9 maskable event interrupts, 7 exception interrupts, 16 trap
interrupts, and 7 software interrupts. The maskable interrupts each
have 8 priority levels and may be globally and/or individually enabled
or disabled.
The XA defines four types of interrupts:
• Exception Interrupts – These are system level errors and other
very important occurrences which include stack overflow,
divide-by-0, and reset.
• Event interrupts – These are peripheral interrupts from devices
such as UARTs, timers, and external interrupt inputs.
• Software Interrupts – These are equivalent of hardware
The complete interrupt vector list for the XA-G3, including all 4
interrupt types, is shown in the following tables. The tables include
the address of the vector for each interrupt, the related priority
register bits (if any), and the arbitration ranking for that interrupt
source. The arbitration ranking determines the order in which
interrupts are processed if more than one interrupt of the same
priority occurs simultaneously.
interrupt, but are requested only under software control.
• Trap Interrupts – These are TRAP instructions, generally used to
call system services in a multi-tasking system.
Exception interrupts, software interrupts, and trap interrupts are
generally standard for XA derivatives and are detailed in the XA
User Guide. Event interrupts tend to be different on different XA
derivatives.
Table 5. Interrupt Vectors
EXCEPTION/TRAPS PRECEDENCE
VECTOR ADDRESS
ARBITRATION RANKING
Reset (h/w, watchdog, s/w)
DESCRIPTION
0000–0003
0 (High)
Breakpoint (h/w trap 1)
0004–0007
1
Trace (h/w trap 2)
0008–000B
1
Stack Overflow (h/w trap 3)
000C–000F
1
Divide by 0 (h/w trap 4)
0010–0013
1
User RETI (h/w trap 5)
0014–0017
1
TRAP 0– 15 (software)
0040–007F
1
EVENT INTERRUPTS
FLAG BIT
VECTOR
ADDRESS
ENABLE BIT
INTERRUPT PRIORITY
ARBITRATION
RANKING
External interrupt 0
IE0
0080–0083
EX0
IPA0.2–0 (PX0)
2
Timer 0 interrupt
TF0
0084–0087
ET0
IPA0.6–4 (PT0)
3
External interrupt 1
IE1
0088–008B
EX1
IPA1.2–0 (PX1)
4
Timer 1 interrupt
TF1
008C–008F
ET1
IPA1.6–4 (PT1)
5
Timer 2 interrupt
TF2(EXF2)
0090–0093
ET2
IPA2.2–0 (PT2)
6
Serial port 0 Rx
RI.0
00A0–00A3
ERI0
IPA4.2–0 (PRIO)
7
Serial port 0 Tx
TI.0
00A4–00A7
ETI0
IPA4.6–4 (PTIO)
8
Serial port 1 Rx
RI.1
00A8–00AB
ERI1
IPA5.2–0 (PRT1)
9
Serial port 1 Tx
TI.1
00AC–00AF
ETI1
IPA5.6–4 (PTI1)
10
FLAG BIT
VECTOR
ADDRESS
ENABLE BIT
INTERRUPT PRIORITY
Software interrupt 1
SWR1
0100–0103
SWE1
(fixed at 1)
Software interrupt 2
SWR2
0104–0107
SWE2
(fixed at 2)
Software interrupt 3
SWR3
0108–010B
SWE3
(fixed at 3)
Software interrupt 4
SWR4
010C–010F
SWE4
(fixed at 4)
Software interrupt 5
SWR5
0110–0113
SWE5
(fixed at 5)
Software interrupt 6
SWR6
0114–0117
SWE6
(fixed at 6)
Software interrupt 7
SWR7
0118–011B
SWE7
(fixed at 7)
DESCRIPTION
SOFTWARE INTERRUPTS
DESCRIPTION
2002 Mar 25
20
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
ABSOLUTE MAXIMUM RATINGS
RATING
UNIT
Operating temperature under bias
PARAMETER
–55 to +125
°C
Storage temperature range
–65 to +150
°C
0 to +13.0
V
Voltage on EA/VPP pin to VSS
Voltage on any other pin to VSS
–0.5 to VDD+0.5 V
V
Maximum IOL per I/O pin
15
mA
Power dissipation (based on package heat transfer limitations, not device power consumption)
1.5
W
DC ELECTRICAL CHARACTERISTICS
VDD = 2.7 V to 5.5 V unless otherwise specified; VDD = Tamb = 0 to 70 °C for commercial, –40 °C to +85 °C for industrial, unless otherwise
specified.
SYMBOL
PARAMETER
TEST CONDITIONS
LIMITS
MIN
TYP
MAX
UNIT
Supplies
IDD
Supply current operating9,10
fosc = 30 MHz
–
60
80
mA
IID
Idle mode supply current9,10
fosc = 30 MHz
–
22
30
mA
IPD
Power-down current
–
–
15
100
mA
IPDI
Power-down current (–40°C to +85°C)
–
–
150
mA
VRAM
RAM-keep-alive voltage
RAM-keep-alive voltage
1.5
–
V
VIL
Input low voltage
–
–0.5
0.22 VDD
V
At 5.0 V
2.2
–
V
At 3.3 V
2
–
V
For both 3.0 & 5.0 V
0.7 VDD
–
V
IOL = 3.2mA, VDD = 5.0 V
–
0.5
V
1.0mA, VDD = 3.0 V
–
0.4
V
IOH = –100mA, VDD = 4.5 V
2.4
–
V
IOH = –15mA, VDD = 2.7 V
2.0
–
V
IOH = 3.2mA, VDD = 4.5 V
2.4
–
V
IOH = 1mA, VDD = 2.7 V
2.2
–
V
–
–
15
pF
VIH
Input
In
ut high voltage
voltage, except
exce t XTAL1
XTAL1, RST
VIH1
Input high voltage to XTAL1, RST
VOL
Output
ALE PSEN3
Out
ut low voltage all ports
orts, ALE,
VOH1
Output
Out
ut high voltage all ports
orts, ALE
ALE, PSEN1
VOH2
Output
voltage ports
P0–3 ALE,
ALE PSEN2
Out
ut high voltage,
orts P0–3,
CIO
Input/Output pin capacitance
IIL
Logical 0 input current, P0–36
VIN = 0.45 V
–
–75
mA
ILI
Input leakage current, P0–35
VIN = VIL or VIH
–
±10
mA
ITL
Logical 1 to 0 transition current all ports4
At 5.5 V
–
–650
mA
–25
NOTES:
1. Ports in Quasi bi-directional mode with weak pull-up (applies to ALE, PSEN only during RESET).
2. Ports in Push-Pull mode, both pull-up and pull-down assumed to be same strength
3. In all output modes
4. Port pins source a transition current when used in quasi-bidirectional mode and externally driven from 1 to 0. This current is highest when
VIN is approximately 2 V.
5. Measured with port in high impedance output mode.
6. Measured with port in quasi-bidirectional output mode.
7. Load capacitance for all outputs=80 pF.
8. Under steady state (non-transient) conditions, IOL must be externally limited as follows:
15 mA (*NOTE: This is 85°C specification for VDD = 5 V.)
Maximum IOL per port pin:
Maximum IOL per 8-bit port:
26 mA
Maximum total IOL for all output: 71 mA
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed
test conditions.
9. See Figures 25, 26, 29, and 30 for IDD test conditions, and Figures 27 and 28 for ICC vs. Frequency.
Max. 5 V Active IDD = (fosc * 1.77 mA) + 7 mA
Max. 5 V Idle IDD = (fosc * 0.87 mA) + 4 mA
Max. 3 V Active IDD = (fosc * 0.77 mA) + 7 mA
Max. 3 V Idle IDD = (fosc * 0.54 mA) + 4 mA
10. VDDMIN = 2.85 V for operating at fOSC = 30 MHz and –40 °C to +85 °C
2002 Mar 25
21
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
AC ELECTRICAL CHARACTERISTICS
VDD = 2.7 V to 5.5 V; Tamb = 0 to +70 °C for commercial, –40 °C to +85 °C for industrial.
VARIABLE CLOCK
SYMBOL
FIGURE
PARAMETER
MIN
MAX
UNIT
External Clock
fC
Oscillator frequency
0
30
MHz
PXAG37KFx
VDD = 2.85 V to 5.5 V
0
30
MHz
Tamb = –40 °C to +85 °C
VDD = 2.7 V to 2.85 V
0
25
MHz
All devices except PXAG37KFx
tC
22
Clock period and CPU timing cycle
1/fC
tCHCX
22
ns
Clock high time
tC * 0.5
tCLCX
ns
22
Clock low time
tC * 0.4
tCLCH
22
Clock rise time
5
ns
tCHCL
22
Clock fall time
5
ns
ns
AC ELECTRICAL CHARACTERISTICS (VDD = 4.5 V TO 5.5 V)
Tamb = 0 to +70 °C for commercial, –40 °C to +85 °C for industrial.
VARIABLE CLOCK
SYMBOL
FIGURE
Address Cycle
tCRAR
21
tLHLL
16
tAVLL
16
tLLAX
16
Code Read Cycle
tPLPH
16
tLLPL
16
tAVIVA
16
tAVIVB
17
tPLIV
16
tPXIX
16
tPXIZ
16
tIXUA
16
Data Read Cycle
tRLRH
18
tLLRL
18
tAVDVA
18
tAVDVB
19
tRLDV
18
tRHDX
18
tRHDZ
18
tDXUA
18
Data Write Cycle
tWLWH
20
tLLWL
20
tQVWX
20
tWHQX
20
tAVWL
20
tUAWH
20
Wait Input
tWTH
21
tWTL
21
NOTES ON PAGE 23.
2002 Mar 25
PARAMETER
UNIT
MIN
MAX
Delay from clock rising edge to ALE rising edge
ALE pulse width (programmable)
Address valid to ALE de-asserted (set-up)
Address hold after ALE de-asserted
10
(V1 * tC) – 6
(V1 * tC) – 12
(tC/2) – 10
46
PSEN pulse width
ALE de-asserted to PSEN asserted
Address valid to instruction valid, ALE cycle (access time)
Address valid to instruction valid, non-ALE cycle (access time)
PSEN asserted to instruction valid (enable time)
Instruction hold after PSEN de-asserted
Bus 3-State after PSEN de-asserted (disable time)
Hold time of unlatched part of address after instruction latched
(V2 * tC) – 10
(tC/2) – 7
RD pulse width
ALE de-asserted to RD asserted
Address valid to data input valid, ALE cycle (access time)
Address valid to data input valid, non-ALE cycle (access time)
RD low to valid data in, enable time
Data hold time after RD de-asserted
Bus 3-State after RD de-asserted (disable time)
Hold time of unlatched part of address after data latched
(V7 * tC) – 10
(tC/2) – 7
0
ns
ns
ns
ns
ns
ns
ns
ns
WR pulse width
ALE falling edge to WR asserted
Data valid before WR asserted (data setup time)
Data hold time after WR de-asserted (Note 6)
Address valid to WR asserted (address setup time) (Note 5)
Hold time of unlatched part of address after WR is de-asserted
(V8 * tC) – 10
(V12 * tC) – 10
(V13 * tC) – 22
(V11 * tC) – 5
(V9 * tC) – 22
(V11 * tC) – 7
ns
ns
ns
ns
ns
ns
WAIT stable after bus strobe (RD, WR, or PSEN) asserted
WAIT hold after bus strobe (RD, WR, or PSEN) assertion
(V10 * tC) – 5
22
(V3 * tC) – 36
(V4 * tC) – 29
(V2 * tC) – 29
0
tC – 8
0
(V6 * tC) – 36
(V5 * tC) – 29
(V7 * tC) – 29
0
tC – 8
(V10 * tC) – 30
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
AC ELECTRICAL CHARACTERISTICS (VDD = 2.7 V TO 4.5 V)
Tamb = 0 to +70 °C for commercial, –40 °C to +85 °C for industrial.
VARIABLE CLOCK
SYMBOL
FIGURE
PARAMETER
MIN
MAX
15
60
UNIT
Address Cycle
tCRAR
21
Delay from clock rising edge to ALE rising edge
ns
tLHLL
16
ALE pulse width (programmable)
(V1 * tC) – 10
ns
tAVLL
16
Address valid to ALE de-asserted (set-up)
(V1 * tC) – 18
ns
tLLAX
16
Address hold after ALE de-asserted
(tC/2) – 12
ns
(V2 * tC) – 12
ns
Code Read Cycle
tPLPH
16
PSEN pulse width
tLLPL
16
ALE de-asserted to PSEN asserted
tAVIVA
16
Address valid to instruction valid, ALE cycle (access time)
(V3 * tC) – 58
ns
tAVIVB
17
Address valid to instruction valid, non-ALE cycle (access time)
(V4 * tC) – 52
ns
tPLIV
16
PSEN asserted to instruction valid (enable time)
(V2 * tC) – 52
ns
tPXIX
16
Instruction hold after PSEN de-asserted
tPXIZ
16
Bus 3-State after PSEN de-asserted (disable time)
tIXUA
16
Hold time of unlatched part of address after instruction latched
tRLRH
18
RD pulse width
tLLRL
18
ALE de-asserted to RD asserted
tAVDVA
18
Address valid to data input valid, ALE cycle (access time)
(V6 * tC) – 58
ns
tAVDVB
19
Address valid to data input valid, non-ALE cycle (access time)
(V5 * tC) – 52
ns
tRLDV
18
RD low to valid data in, enable time
(V7 * tC) – 52
ns
tRHDX
18
Data hold time after RD de-asserted
tRHDZ
18
Bus 3-State after RD de-asserted (disable time)
tDXUA
18
Hold time of unlatched part of address after data latched
tWLWH
20
tLLWL
20
tQVWX
tWHQX
(tC/2) – 9
ns
0
ns
tC – 8
ns
0
ns
(V7 * tC) – 12
ns
(tC/2) – 9
ns
Data Read Cycle
0
ns
tC – 8
ns
0
ns
WR pulse width
(V8 * tC) – 12
ns
ALE falling edge to WR asserted
(V12 * tC) – 10
ns
20
Data valid before WR asserted (data setup time)
(V13 * tC) – 28
ns
20
Data hold time after WR de-asserted (Note 6)
(V11 * tC) – 8
ns
tAVWL
20
Address valid to WR asserted (address setup time) (Note 5)
(V9 * tC) – 28
ns
tUAWH
20
Hold time of unlatched part of address after WR is de-asserted
(V11 * tC) – 10
ns
tWTH
21
WAIT stable after bus strobe (RD, WR, or PSEN) asserted
tWTL
21
WAIT hold after bus strobe (RD, WR, or PSEN) assertion
Data Write Cycle
Wait Input
(V10 * tC) – 40
(V10 * tC) – 5
ns
ns
NOTES:
1. Load capacitance for all outputs = 80 pF.
2. Variables V1 through V13 reflect programmable bus timing, which is programmed via the Bus Timing registers (BTRH and BTRL).
Refer to the XA User Guide for details of the bus timing settings.
V1) This variable represents the programmed width of the ALE pulse as determined by the ALEW bit in the BTRL register.
V1 = 0.5 if the ALEW bit = 0, and 1.5 if the ALEW bit = 1.
V2) This variable represents the programmed width of the PSEN pulse as determined by the CR1 and CR0 bits or the CRA1, CRA0, and
ALEW bits in the BTRL register.
– For a bus cycle with no ALE, V2 = 1 if CR1/0 = 00, 2 if CR1/0 = 01, 3 if CR1/0 = 10, and 4 if CR1/0 = 11. Note that during burst
mode code fetches, PSEN does not exhibit transitions at the boundaries of bus cycles. V2 still applies for the purpose of
determining peripheral timing requirements.
– For a bus cycle with an ALE, V2 = the total bus cycle duration (2 if CRA1/0 = 00, 3 if CRA1/0 = 01, 4 if CRA1/0 = 10,
and 5 if CRA1/0 = 11) minus the number of clocks used by ALE (V1 + 0.5).
Example: If CRA1/0 = 10 and ALEW = 1, the V2 = 4 – (1.5 + 0.5) = 2.
2002 Mar 25
23
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
V3)
3.
4.
5.
6.
This variable represents the programmed length of an entire code read cycle with ALE. This time is determined by the CRA1 and
CRA0 bits in the BTRL register. V3 = the total bus cycle duration (2 if CRA1/0 = 00, 3 if CRA1/0 = 01, 4 if CRA1/0 = 10,
and 5 if CRA1/0 = 11).
V4) This variable represents the programmed length of an entire code read cycle with no ALE. This time is determined by the CR1 and
CR0 bits in the BTRL register. V4 = 1 if CR1/0 = 00, 2 if CR1/0 = 01, 3 if CR1/0 = 10, and 4 if CR1/0 = 11.
V5) This variable represents the programmed length of an entire data read cycle with no ALE. this time is determined by the DR1 and
DR0 bits in the BTRH register. V5 = 1 if DR1/0 = 00, 2 if DR1/0 = 01, 3 if DR1/0 = 10, and 4 if DR1/0 = 11.
V6) This variable represents the programmed length of an entire data read cycle with ALE. The time is determined by the DRA1 and
DRA0 bits in the BTRH register. V6 = the total bus cycle duration (2 if DRA1/0 = 00, 3 if DRA1/0 = 01, 4 if DRA1/0 = 10,
and 5 if DRA1/0 = 11).
V7) This variable represents the programmed width of the RD pulse as determined by the DR1 and DR0 bits or the DRA1, DRA0 in the
BTRH register, and the ALEW 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 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.
V8) This variable represents the programmed width of the WRL and/or WRH pulse as determined by the WM1 bit in the BTRL register.
V8 1 if WM1 = 0, and 2 if WM1 = 1.
V9) This variable represents the programmed address setup time for a write as determined by the data write cycle duration (defined by
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
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.
– 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
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 = 11, WM0 = 1, and WM1 = 0, then V9 = 5 – 1 – 1 = 3.
V10) This variable represents the length of a bus strobe for calculation of WAIT setup and hold times. The strobe may be RD (for data 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 = V2 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.
V11) 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.
V12) This variable represents the programmed period between the end of the ALE pulse and the beginning of the WRL and/or WRH pulse
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
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
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 DWA1/0 = 11, WM0 = 1, WM1 = 0, and ALEW = 1, then V12 = 5 – 1 – 1 – 1.5 = 1.5.
V13) This variable represents the programmed data setup time for a write as determined by the data write cycle duration (defined by DW1
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
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.
– 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
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.
Not all combinations of bus timing configuration values result in valid bus cycles. Please refer to the XA User Guide section on the External
Bus for details.
When code is being fetched for execution on the external bus, a burst mode fetch is used that does not have PSEN edges in every fetch
cycle. Thus, if WAIT is used to delay code fetch cycles, a change in the low order address lines must be detected to locate the beginning of
a cycle. This would be A3–A0 for an 8-bit bus, and A3–A1 for a 16-bit bus. Also, a 16-bit data read operation conducted on a 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.
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,
and in most applications this parameter is not used.
Please note that the XA-G37 requires that extended data bus hold time (WM0 = 1) to be used with external bus write cycles.
2002 Mar 25
24
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
tLHLL
ALE
tAVLL
tLLPL
tPLPH
tPLIV
PSEN
tLLAX
MULTIPLEXED
ADDRESS AND DATA
tPLAZ
tPXIX
INSTR IN *
A4–A19
tIXUA
tAVIVA
UNMULTIPLEXED
ADDRESS
*
tPXIZ
A1–A3
D0–D15
SU00946
Figure 16. External Program Memory Read Cycle (ALE Cycle)
ALE
PSEN
MULTIPLEXED
ADDRESS AND DATA
A4–A11 or A4–A19
INSTR IN *
tAVIVB
UNMULTIPLEXED
ADDRESS
*
A0 or A1–A3, A12–19
A0 or A1–A3, A12–19
INSTR IN is either D0–D7 or D0–D15, depending on the bus width (8 or 16 bits).
Figure 17. External Program Memory Read Cycle (Non-ALE Cycle)
2002 Mar 25
25
SU00707
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
ALE
tLLRL
RD
tAVLL
tRLRH
tLLAX
tRHDZ
tRLDV
tRHDX
MULTIPLEXED
ADDRESS
AND DATA
A4–A11 or A4–A19
DATA IN
*
tDXUA
tAVDVA
UNMULTIPLEXED
ADDRESS
*
A0 or A1–A3, A12–A19
DATA IN is either D0–D7 or D0–D15, depending on the bus width (8 or 16 bits).
SU00947
Figure 18. External Data Memory Read Cycle (ALE Cycle)
ALE
RD
MULTIPLEXED
ADDRESS
AND DATA
D0–D7
A4–A11
DATA IN
*
tAVDVB
UNMULTIPLEXED
ADDRESS
A0–A3, A12–A19
A0–A3, A12–A19
SU00708A
Figure 19. External Data Memory Read Cycle (Non-ALE Cycle) 8 Bit Bus Only
2002 Mar 25
26
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
ALE
tWLWH
tLLWL
WRL or WRH
tLLAX
tAVLL
MULTIPLEXED
ADDRESS
AND DATA
tQVWX
tWHQX
DATA OUT *
A4–A11 or A4–A15
tAVWL
tUAWH
UNMULTIPLEXED
ADDRESS
*
A0 or A1–A3, A12–A19
DATA OUT is either D0–D7 or D0–D15, depending on the bus width (8 or 16 bits).
SU00584C
Figure 20. External Data Memory Write Cycle
XTAL1
tCRAR
ALE
ADDRESS BUS
WAIT
BUS STROBE
(WRL, WRH,
RD, OR PSEN)
tWTH
(The dashed line shows the strobe without WAIT.)
tWTL
SU00709A
Figure 21. WAIT Signal Timing
2002 Mar 25
27
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
VDD–0.5
0.7VDD
0.2VDD–0.1
0.45V
tCHCL
tCHCX
tCLCH
tCLCX
tC
SU00842
Figure 22. External Clock Drive
VDD–0.5
0.2VDD+0.9
0.2VDD–0.1
0.45V
NOTE:
AC inputs during testing are driven at VDD –0.5 for a logic ‘1’ and 0.45V for a logic ‘0’.
Timing measurements are made at the 50% point of transitions.
SU00703A
Figure 23. AC Testing Input/Output
VLOAD+0.1V
VOH–0.1V
TIMING
REFERENCE
POINTS
VLOAD
VLOAD–0.1V
VOL+0.1V
NOTE:
For timing purposes, a port is no longer floating when a 100mV change from load voltage occurs,
and begins to float when a 100mV change from the loaded VOH/VOL level occurs. IOH/IOL ≥ ±20mA.
SU00011
Figure 24. Float Waveform
VDD
VDD
VDD
VDD
RST
VDD
RST
EA
EA
(NC)
XTAL2
(NC)
XTAL2
CLOCK SIGNAL
XTAL1
CLOCK SIGNAL
XTAL1
VSS
VSS
SU00591B
SU00590B
Figure 25. IDD Test Condition, Active Mode
All other pins are disconnected
2002 Mar 25
Figure 26. IDD Test Condition, Idle Mode
All other pins are disconnected
28
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
80
MAX. IDD (ACTIVE)
70
60
TYPICAL IDD (ACTIVE)
50
mA
40
30
MAX. IDD (IDLE)
TYPICAL IDD (IDLE)
20
10
0
0
5
10
15
20
25
30
FREQUENCY
SU01661
Figure 27. IDD vs. Frequency at VDD = 5.0 V
30
MAX. IDD (ACTIVE)
25
TYPICAL IDD (ACTIVE)
mA
20
MAX. IDD (IDLE)
15
TYPICAL IDD (IDLE)
10
5
0
0
5
10
15
20
FREQUENCY
Figure 28. IDD vs. Frequency at VDD = 3.0 V
2002 Mar 25
29
25
30
SU01193
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
VDD–0.5
0.7VDD
0.2VDD–0.1
0.45V
tCHCL
tCHCX
tCLCH
tCLCX
tCL
SU00608A
Figure 29. Clock Signal Waveform for IDD Tests in Active and Idle Modes
tCLCH = tCHCL = 5ns
VDD
VDD
VDD
RST
EA
(NC)
XTAL2
XTAL1
VSS
SU00585A
Figure 30. IDD Test Condition, Power Down Mode
All other pins are disconnected. VDD=2 V to 5.5 V
2002 Mar 25
30
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
EPROM CHARACTERISTICS
Security Bits
The XA-G37 is programmed by using a modified Improved
Quick-Pulse Programming algorithm. This algorithm is essentially
the same as that used by the later 80C51 family EPROM parts.
However different pins are used for many programming functions.
With none of the security bits programmed the code in the program
memory can be verified. When only security bit 1 (see Table 6) is
programmed, MOVC instructions executed from external program
memory are disabled from fetching code bytes from the internal
memory. All further programming of the EPROM is disabled. When
security bits 1 and 2 are programmed, in addition to the above,
verify mode is disabled. When all three security bits are
programmed, all of the conditions above apply and all external
program memory execution is disabled. (See Table 6)
Detailed EPROM programming information may be obtained from
the internet at www.philipsmcu.com/ftp.html.
The XA-G37 contains three signature bytes that can be read and
used by an EPROM programming system to identify the device. The
signature bytes identify the device as an XA-Gx manufactured by
Philips.
Table 6. Program Security Bits
PROGRAM LOCK BITS
SB1
SB2
SB3
PROTECTION DESCRIPTION
1
U
U
U
No Program Security features enabled.
2
P
U
U
MOVC instructions executed from external program memory are disabled from fetching code bytes
from internal memory and further programming of the EPROM is disabled.
3
P
P
U
Same as 2, also verify is disabled.
4
P
P
P
Same as 3, external execution is disabled. Internal data RAM is not accessible.
NOTES:
1. P – programmed. U – unprogrammed.
2. Any other combination of the security bits is not defined.
Trademark phrase of Intel Corporation.
2002 Mar 25
31
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
LQFP44: plastic low profile quad flat package; 44 leads; body 10 x 10 x 1.4 mm
2002 Mar 25
32
SOT389-1
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
PLCC44: plastic leaded chip carrier; 44 leads
2002 Mar 25
SOT187-2
33
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
REVISION HISTORY
Date
CPCN
Description
2002 Mar 25
9397 750 09585
– Deleted information for XA-G33
– Spun off XA-G30 into a separate data sheet
– Corrected Figure 27 (IDD vs. Frequency)
– Corrected typical power down current to 15 µA
2001 Jun 25
2002 Mar 25
9397 750 08554
Previous release
34
Philips Semiconductors
Product data
XA 16-bit microcontroller family
XA-G37
32K OTP, 512 B RAM, watchdog, 2 UARTs
Data sheet status
Data sheet status [1]
Product
status [2]
Definitions
Objective data
Development
This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.
Preliminary data
Qualification
This data sheet contains data from the preliminary specification. Supplementary data will be
published at a later date. Philips Semiconductors reserves the right to change the specification
without notice, in order to improve the design and supply the best possible product.
Product data
Production
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply.
Changes will be communicated according to the Customer Product/Process Change Notification
(CPCN) procedure SNW-SQ-650A.
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
 Koninklijke Philips Electronics N.V. 2002
All rights reserved. Printed in U.S.A.
Contact information
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
Date of release: 03-02
For sales offices addresses send e-mail to:
[email protected].
Document order number:
2002 Mar 25
35
9397 750 09585