HD64F2638F20J Renesas Electronics America, HD64F2638F20J Datasheet - Page 148
Manufacturer Part Number
IC H8S MCU FLASH 256K 128-QFP
Renesas Electronics America
Specifications of HD64F2638F20J
CAN, SCI, SmartCard
Motor Control PWM, POR, PWM, WDT
Number Of I /o
Program Memory Size
256KB (256K x 8)
Program Memory Type
16K x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
A/D 12x10b; D/A 2x8b
-40°C ~ 85°C
Package / Case
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Section 2 Instruction Descriptions
MAC (Multiply and ACcumulate)
Operand Format and Number of States Required for Execution
1. Flags (N, Z, V) indicating the result of the MAC instruction can be set in the condition-code
2. If ERn and ERm are the same register, the execution addresses are ERn and ERn + 2. After
3. If MACS is modified during execution of a MAC instruction, the result cannot be guaranteed.
Further Explanation of Instructions Using Multiplier
1. Modification of flags
Rev. 4.00 Feb 24, 2006 page 132 of 322
register (CCR) by the STMAC instruction.
execution, the value of ERn is ERn + 4.
It is essential to wait for at least three states after a MAC instruction before modifying MACS.
The multiplier has N-MULT, Z-MULT, and V-MULT flags that indicate the results of MAC
instructions. These flags are separated from the condition-code register (CCR). The values of
these flags can be set in the N, Z, and V flags of the CCR only by the STMAC instruction.
N-MULT and Z-MULT are modified only by MAC instructions. V-MULT retains a value
indicating whether an overflow has occurred in the past, until it is cleared by execution of the
CLRMAC or LDMAC instruction.
The setting and clearing conditions for these flags are given below.
N-MULT (negative flag)
Set when bit 31 of register MACL is set to 1 by execution of a
Cleared when bit 31 of register MACL is cleared to 0 by execution
of a MAC instruction
Set when bit 41 of register MACH is set to 1 by execution of a
Cleared when bit 41 of register MACH is cleared to 0 by execution
of a MAC instruction
Multiply and Accumulate