k2 816 Core2x: inconsistent reports when reading the MAC address in 24-bit mode vs MMU mode.

[ghackwrench]

See below for reproduce.

Hardware version

• Machine type: Wildbits/K2
• PCB revision: black board
• CPU: 65816
• Speed: 2x

[ghackwrench]

get_mac
    ; IN: Y=buffer
            phy

            ldy     #0
          - tya
            clc
            adc     #$a0fa    ; a0:fa..ff slave:address.

            jsr     i2c.dev_get
            bcs     +

            sep     #$20
            sta     (1,s),y
            rep     #$20

            iny
            cpy     #6
            bne -
            clc

          + ply
            rts

i2c.dev_get
    ; IN:   A = slave:address.
    ; OUT:  A = byte at address.

            sep     #$20

            sta     ADDR
            xba
            sta     SLAVE
            lda     #2
            sta     COUNT

          ; Strobe the read.
            lda     #CTRL_READ
            sta     CTRL
            lda     #0
            sta     CTRL

          ; Wait for data;
            phy
            ldy     #0
          - cpy     #$2000
            bcs +
            lda     CTRL
            bpl +
            iny
            bra -
          + ply
            bcs +

          ; Read the data out of the queue.
            lda     DATA

          + rep     #$20
            and     #$ff
            rts

core2x, MMU mode: 44:44:b7:d0:db:07
core2x, 24-bit mode: 44:b7:d0:db:07:9b