sdcc-sdld: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/sdcc-sdld - from package: sdcc

You may install the required package with command yum install {package}
Error in other languages:
sdcc-sdld: bevel nie gevind nie
sdcc-sdld: comandă negăsită
sdcc-sdld: comando não encontrado
sdcc-sdld: commande introuvable
sdcc-sdld: command not found
sdcc-sdld: käsku ei ole
sdcc-sdld: không tìm thấy lệnh
sdcc-sdld: komanda nerasta
sdcc-sdld: Kommando nicht gefunden.
sdcc-sdld: kommandot finns inte
sdcc-sdld: komut yok
sdcc-sdld: nie znaleziono polecenia
sdcc-sdld: níor aimsíodh an t-ordú
sdcc-sdld: no se encontró la orden
sdcc-sdld: no s'ha trobat l'ordre
sdcc-sdld: opdracht niet gevonden
sdcc-sdld: parancs nem található
sdcc-sdld: perintah tidak ditemukan
sdcc-sdld: príkaz nenájdený
sdcc-sdld: příkaz nenalezen
sdcc-sdld: команда не найдена
sdcc-sdld: командата не е открита
sdcc-sdld: 命令找不到
sdcc-sdld: コマンドが見つかりません