SDA6000 Datasheet, PDF (82/380 Pages) Infineon Technologies AG – Teletext Decoder with Embedded 16-bit Controller

SDA 6000
C16X Microcontroller
SUB instructions or by PUSH or POP operations (explicit or implicit, i.e. CALL or RET
instructions).
This control mechanism is not triggered, i.e. no stack trap is generated, when
• the stack pointer SP is directly updated via MOV instructions
• the limits of the stack area (STKOV, STKUN) are changed, so that SP is outside of
the new limits.
The Multiply/Divide High Register MDH
This register is a part of the 32-bit multiply/divide register, which is implicitly used by the
CPU, when it performs a multiplication or a division. After a multiplication, this non-bit
addressable register represents the high order 16 bits of the 32-bit result. For long
division, the MDH register must be loaded with the high order 16 bits of the 32-bit
dividend before the division is started. After any division, the MDH register represents
the 16-bit remainder.
MDH
Reset Value: 0000_H
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
mdh
rw
Bit
mdh
Function
Specifies the high order 16 bits of the 32-bit multiply and divide register
MD.
Whenever this register is updated via software, the Multiply/Divide Register In Use
(MDRIU) flag in the Multiply/Divide Control register (MDC) is set to ‘1’.
When multiplication or division is interrupted before its completion and when a new
multiply or divide operation is to be performed within the interrupt service routine, the
MDH register must be saved along with the MDL and MDC registers to avoid erroneous
results.
The Multiply/Divide Low Register MDL
This register is a part of the 32-bit multiply/divide register which is implicitly used by the
CPU when it performs a multiplication or a division. After multiplication, this non-bit
addressable register represents the low order 16 bits of the 32-bit result. For long
division, the MDL register must be loaded with the low order 16 bits of the 32-bit dividend
before the division is started. After any division, the MDL register represents the 16-bit
quotient.
Users Manual
4 - 49
2000-06-15